NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2016.

Cover of GeneReviews®

GeneReviews® [Internet].

Show details

Glycogen Storage Disease Type II (Pompe Disease)

Synonyms: Acid Alpha-Glucosidase Deficiency, Acid Maltase Deficiency, GAA Deficiency, GSD II, Glycogenosis Type II

, MD and , MD, PhD.

Author Information
, MD
Cincinnati STAR Center for Lysosomal Diseases
Division of Human Genetics
Cincinnati Children's Hospital Medical Center
Cincinnati, Ohio
, MD, PhD
Advocate Medical Genetics
Advocate Children’s Hospital
Park Ridge, Illinois

Initial Posting: ; Last Update: May 9, 2013.


Clinical characteristics.

Glycogen storage disease type II (GSD II), or Pompe disease, is classified by age of onset, organ involvement, severity, and rate of progression. Classic infantile-onset Pompe disease may be apparent in utero but more often presents in the first two months of life with hypotonia, generalized muscle weakness, cardiomegaly and hypertrophic cardiomyopathy, feeding difficulties, failure to thrive, respiratory distress, and hearing loss. Without treatment by enzyme replacement therapy (ERT), classic infantile-onset Pompe disease commonly results in death in the first year of life from progressive left ventricular outflow obstruction. The non-classic variant of infantile-onset Pompe disease usually presents within the first year of life with motor delays and/or slowly progressive muscle weakness, typically resulting in death from ventilatory failure in early childhood. Cardiomegaly can be seen, but heart disease is not a major source of morbidity. Late-onset (i.e., childhood, juvenile, and adult-onset) Pompe disease is characterized by proximal muscle weakness and respiratory insufficiency; clinically significant cardiac involvement is uncommon in the late-onset form.


Measurement of acid alpha-glucosidase (GAA) enzyme activity is diagnostic. GAA is the only gene in which mutation is known to cause GSD II.


Treatment of manifestations: Management guidelines from the American College of Medical Genetics: individualized care of cardiomyopathy as standard drugs may be contraindicated and risk for tachyarrhythmia and sudden death is high; physical therapy for muscle weakness to maintain range of motion and assist in ambulation; surgery for contractures as needed; nutrition/feeding support. Respiratory support may include inspiratory/expiratory training in affected adults, CPAP, BiPAP and/or tracheostomy.

Prevention of primary manifestations: Begin enzyme replacement therapy (ERT) with Myozyme® or Lumizyme® (alglucosidase alfa) as soon as the diagnosis is established. Infants at high risk for development of antibodies to the therapeutic enzyme are likely to need an immunomodulatory protocol early in the treatment course. In the pivotal trial, a majority of infants in whom ERT was initiated before age six months and before the need for ventilatory assistance demonstrated improved survival, ventilator-independent survival, improved acquisition of motor skills, and reduced cardiac mass compared to untreated controls. In affected individuals with late-onset disease, ERT may stabilize ventilatory function and motor ability, measured by six-minute walk and upright pulmonary function testing. ERT can be accompanied by treatable infusion reactions as well as anaphylaxis.

Prevention of secondary complications: Aggressive management of infections; keeping immunizations up to date; annual influenza vaccination of the affected individual and household members; respiratory syncytial virus (RSV) prophylaxis (palivizumab) in the first two years of life; use of anesthesia only when absolutely necessary.

Surveillance: Routine monitoring of respiratory status, cardiovascular status, musculoskeletal function (including bone densitometry), nutrition and feeding, renal function, and hearing.

Agents/circumstances to avoid: Digoxin, ionotropes, diuretics, and afterload-reducing agents, as they may worsen left ventricular outflow obstruction in some stages of the disease; hypotension and volume depletion; exposure to infectious agents.

Evaluation of relatives at risk: Evaluate at-risk sibs by GAA enzyme activity or molecular genetic testing (if the pathogenic variants have been identified in an affected family member) to permit early diagnosis and treatment with ERT.

Genetic counseling.

GSD II (Pompe disease) is inherited in an autosomal recessive manner. In most instances, the parents of a proband are heterozygotes and thus carry a single copy of a GAA pathogenic variant. Heterozygotes (carriers) are asymptomatic. At conception, each sib of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier. Historically, children with classic infantile Pompe disease have not survived to reproduce, whereas many individuals with later-onset disease survive into their 50s and 60s. Carrier testing for at-risk family members and prenatal testing for pregnancies at increased risk are possible if the pathogenic variants in the family are known.


Clinical Diagnosis

The two general subtypes of glycogen storage disease type II (GSD II), also known as Pompe disease, differ by age of onset and clinical findings.

Infantile-onset Pompe disease is suspected in infants with the following [van den Hout et al 2003, Kishnani et al 2006a]:

  • Poor feeding/failure to thrive (44%-97% of cases)
  • Motor delay/muscle weakness (20%-63%)
  • Respiratory concerns (infections/difficulty) (27%-78%)
  • Cardiac problems (shortened PR interval with a broad, wide QRS complex, cardiomegaly, left ventricular outflow obstruction, cardiomyopathy) (50%-92%)

Late-onset (i.e., childhood, juvenile, and adult-onset) Pompe disease is suspected in individuals with proximal muscular weakness and respiratory insufficiency without clinically apparent cardiac involvement.


Nonspecific tests used to support the diagnosis of Pompe disease

  • Serum creatine kinase (CK) concentration is uniformly elevated (as high as 2000 IU/L; normal: 60-305 IU/L) in classic infantile-onset Pompe disease and in the childhood and juvenile variants, but may be normal in adult-onset disease [Laforêt et al 2000, Kishnani et al 2006b]. However, serum CK concentration is elevated in many conditions and must be considered nonspecific.
  • Urinary oligosaccharides. Elevation of a specific urinary glucose tetrasaccharide is highly sensitive in Pompe disease but is also seen in other glycogen storage diseases [An et al 2000, Kallwass et al 2007, Young et al 2012].

Testing used to establish the diagnosis of Pompe disease

  • Acid alpha-glucosidase (GAA) enzyme activity. GAA enzyme activity analysis can be performed on dried blood spots [Chamoles et al 2004, Zhang et al 2006, Pompe Disease Diagnostic Working Group 2008], thus permitting rapid and sensitive analysis. Standard conditions for assay of GAA in blood samples have been proposed by a Pompe Disease Diagnostic Working Group. Confirmation by measurement of GAA activity in another tissue (e.g., culture skin fibroblasts) or molecular analysis is recommended [Pompe Disease Diagnostic Working Group 2008]. Historically, measurement of GAA enzyme activity has been performed using cultured skin fibroblasts, but it may take four to six weeks to obtain results, and delayed diagnosis and initiation of treatment, particularly in infants, may affect outcome.
    • Complete deficiency (activity <1% of normal controls) of GAA enzyme activity is associated with classic infantile-onset Pompe disease.
    • Partial deficiency (activity 2%-40% of normal controls) of GAA enzyme activity is associated with the non-classic infantile-onset and the late-onset forms [Hirschhorn & Reuser 2001].

      Note: (1) As a general rule, the lower the GAA enzyme activity the earlier the age of onset of disease. (2) GAA enzyme activity can be assayed in muscle; however, this invasive procedure usually requires anesthesia, which may not be tolerated in those who have infantile Pompe disease and cardiopulmonary compromise. (3) Peripheral leukocytes have been used to measure GAA enzyme activity but alternate isoenzymes such as maltase-glucoamylase may interfere with the assay. (4) GAA enzyme activity analysis can be performed on dried blood spots [Chamoles et al 2004, Zhang et al 2006], thus permitting rapid and sensitive analysis that is potentially useful for newborn screening [Kishnani et al 2006b].
  • Acid alpha-glucosidase protein quantitation can be performed by an antibody-based method in cultured fibroblasts. Such testing may be important in determining if an affected individual produces cross-reactive immunologic material (CRIM). CRIM status affects response to ERT and CRIM-negative individuals need an altered plan for enzyme therapy [Pompe Disease Diagnostic Working Group 2008, Kishnani et al 2010, Messinger et al 2012].
  • Muscle biopsy. In contrast to the other glycogen storage disorders, GSD II is also a lysosomal storage disease. In GSD II glycogen storage may be observed in the lysosomes of muscle cells as vacuoles of varying severity that stain positively with periodic acid-Schiff. However, 20%-30% of individuals with late-onset Pompe disease with documented partial enzyme deficiency may not show these muscle-specific changes [Laforêt et al 2000, Winkel et al 2005].

Newborn screening. Newborn screening for GSD II, using GAA enzyme activity in dried blood spots as a primary screening tool, has been under study in Taiwan. Variants associated with infantile-onset and late-onset disease have been identified in the Taiwanese population. A nationwide study in Austria using enzymatic activity followed by mutation analysis identified one newborn among 34,736 samples [Mechtler et al 2012]. Similar feasibility studies have occurred in Japan [Oda et al 2011]. Pilot trials in the US are planned in several states.

The rationale for newborn screening is that infants with confirmed infantile-onset GSD II (Pompe disease) who are treated early with ERT have demonstrated improved cardiac status and motor gains, when compared to controls [Chien et al 2009].

Cautions: (1) The pseudodeficiency allele c.1726 G>A (p.Gly576Ser), which is relatively common in Asian populations, complicates the assessment and diagnostic confirmation in these populations. It remains to be seen whether pseudodeficiency is common in other populations [Labrousse et al 2010]. (2) In areas in which pathogenic variants that result in CRIM-negative proteins are more common (e.g., the US, the Middle East), newborn screening to facilitate early diagnosis and hence initiation of ERT may not provide much improvement unless alternative therapy protocols using immunomodulation are considered [Messinger et al 2012].

Molecular Genetic Testing

Gene. GAA is the only gene in which mutation is known to cause GSD II.

Clinical testing

Table 1.

Summary of Molecular Genetic Testing Used in Glycogen Storage Disease Type II (Pompe Disease)

Gene 1Test MethodAllelic Variants Detected 2Mutation Detection Frequency by Test Method 3
GAASequence analysis 4p.Arg854Ter~50%-60% 5
p.Asp645Glu~40%-80% 6
c.336-13T>G~50%-85% 7
Other sequence variants in the gene83%-93% 8
Sequence analysis of select exonsSequence variants in the select exons 983%-93% 6
Targeted mutation analysisSequence variants in targeted sites 9100% among the targeted variants
Deletion/duplication analysis 10Exon and whole-gene deletions/duplications5%-13% 11

See Molecular Genetics for information on allelic variants.


The ability of the test method used to detect a pathogenic variant that is present in the indicated gene


Sequence analysis detects variants that are benign, likely benign, of uncertain significance, likely pathogenic, or pathogenic. Pathogenic variants may include small intragenic deletions/insertions and missense, nonsense, and splice site variants; typically, exon or whole-gene deletions/duplications are not detected. For issues to consider in interpretation of sequence analysis results, click here.


In African Americans with infantile-onset Pompe disease [Becker et al 1998, Hirschhorn & Reuser 2001]


In individuals of Chinese ancestry with infantile Pompe disease [Shieh & Lin 1998, Ko et al 1999, Hirschhorn & Reuser 2001]


In adults with late-onset disease; typically this variant occurs in the compound heterozygous state [Laforêt et al 2000, Hirschhorn & Reuser 2001, Winkel et al 2005, Montalvo et al 2006].


Detection rate of two variants in sequencing of the genomic DNA in patients with confirmed reduced or absent GAA enzyme activity [Hermans et al 2004, Montalvo et al 2006]


Targeted mutations and select exons may vary by laboratory


Testing that identifies exon or whole-gene deletions/duplications not readily detectable by sequence analysis of the coding and flanking intronic regions of genomic DNA; included in the variety of methods that may be used are: quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray (CMA) that includes this gene/chromosome segment.


Deletion/duplication analysis. One of the more common pathogenic alleles involves the deletion of exon 18, seen in approximately 5%-7% of alleles [Van der Kraan et al 1994]. Exon and multiexon deletions have been seen. With the exception of deletion of exon 18, such deletions are rare except in consanguineous unions [McCready et al 2007, Pittis et al 2008, Bali et al 2012].

Testing Strategy

To confirm/establish the diagnosis in a proband. Guidelines for the diagnosis of Pompe disease have been put forth by an expert panel from the American College of Medical Genetics [Kishnani et al 2006b].

Clinical evaluation alone is not sufficient to establish the diagnosis of any of the forms of Pompe disease:

  • Assay of acid alpha-glucosidase (GAA) enzyme activity in cultured skin fibroblasts or muscle, considered the gold standard for diagnosis, is the diagnostic test of choice if feasible, but it may take weeks to obtain results.
  • Assay of GAA enzyme activity in whole blood or dried bloodspot reliably detects GAA enzyme deficiency; confirmation by a second method is preferred prior to initiation of therapy [Kallwass et al 2007, Pompe Disease Diagnostic Working Group 2008].
  • Urinary tetrasaccharide levels are elevated in nearly 100% of individuals with infantile Pompe disease, but may be normal in late-onset disease [Young et al 2009].
    Note: Histochemical evidence of glycogen storage in muscle is supportive of a glycogen storage disorder but not specific for Pompe disease.

Identification of two disease-causing GAA alleles using molecular genetic testing provides additional confirmation of the diagnosis.

  • Depending on ethnicity and phenotype, an individual could be tested first for one of the three common pathogenic variants — p.Asp645Glu, p.Arg854Ter, and c.336-13T>G — before proceeding to full gene sequence analysis.
  • Molecular analysis is an important element in the rapid assessment of cross-reactive immunologic material (CRIM) status in infantile Pompe [Bali et al 2012]. Experience with molecular analysis as the sole diagnostic test is limited, particularly in individuals who are asymptomatic or lacking sentinel clinical findings.

Carrier testing for at-risk relatives using molecular genetic testing requires prior identification of the GAA pathogenic variants in the family.

Note: Carriers are heterozygotes for this autosomal recessive disorder and are not at risk of developing the disorder.

Predictive testing for at-risk asymptomatic family members using molecular genetic testing requires prior identification of the GAA pathogenic variants in the family.

Prenatal diagnosis and preimplantation genetic diagnosis (PGD) for at-risk pregnancies require prior identification of the pathogenic variants in the family.

Clinical Characteristics

Clinical Description

Glycogen storage disease type II (GSD II; Pompe disease) has been classified based on age of onset, organ involvement, severity, and rate of progression. As a general rule, the earlier the onset of symptoms, the faster the rate of progression.

Although "late-onset" Pompe disease has been divided into childhood, juvenile, and adult-onset forms, many persons with the adult-onset type recall symptoms beginning in childhood and thus, "late-onset" is often the preferred term for those presenting after the first few years of life [Laforêt et al 2000]. Most likely, late-onset Pompe disease represents a clinical continuum in which subtypes cannot be reliably distinguished by age of onset.

Classic infantile-onset Pompe disease may be apparent in utero but more often presents in the first two months of life as hypotonia, generalized muscle weakness, feeding difficulties, failure to thrive, and respiratory distress (see Table 2).

Feeding difficulties may result from facial hypotonia, macroglossia, tongue weakness, and/or poor oromotor skills [van Gelder et al 2012].

Hearing abnormalities are common, possibly reflecting a cochlear or conductive pathology or both [Kamphoven et al 2004, van Capelle et al 2010].

Without treatment by enzyme replacement therapy (ERT), the cardiomegaly and hypertrophic cardiomyopathy that are often identified at birth by echocardiography progress to left ventricular outflow obstruction. Enlargement of the heart can also result in diminished lung volumes, atelectasis, and sometimes bronchial compression. Progressive deposition of glycogen results in conduction defects as seen by shortening of the PR interval on ECG.

In untreated infants, death commonly occurs in the first year of life from cardiopulmonary insufficiency [van den Hout et al 2003, Kishnani et al 2006a].

Table 2.

Common Findings at Presentation of Infantile Pompe Disease

Physical SignsProportion of Cases 1
Hypotonia/muscle weakness52%-96%
Left ventricular hypertrophy83%-100%
Respiratory distress41%-78%
Enlarged tongue (macroglossia)29%-62%
Feeding difficulties57%
Failure to thrive53%
Absent deep tendon reflexes33%-35%
Normal cognition95%

The non-classic variant of infantile-onset Pompe disease usually presents within the first year of life predominantly with motor delays and/or muscle weakness. Muscles are firm and rubbery as a result of glycogen deposition. Pseudohypertrophy of the calf muscles and a Gower sign simulate Duchenne muscular dystrophy (DMD), but these findings typically occur at an earlier age in Pompe disease than in DMD. Muscular weakness progresses more slowly than in classic infantile-onset Pompe disease.

Cardiomegaly can be seen with or without left ventricular outflow obstruction; it is not a major source of clinical morbidity [Slonim et al 2000].

Death from ventilatory failure typically occurs in early childhood.

Late-onset Pompe disease can present at various ages with muscle weakness and respiratory insufficiency. Progression of the disease is often predicted by the age of onset, as progression is more rapid if symptoms present in childhood.

Late-onset Pompe disease presenting in infancy or early childhood may be difficult to differentiate from the non-classic infantile form. Cardiomegaly is not typically seen but progressive muscle weakness resulting in motor delays, swallowing difficulties, and respiratory insufficiency usually occurs as in the infantile form, but at a slower rate.

While initial symptom presentation in late childhood to adolescence is typically not associated with heart complications, some adults with late onset disease have been found to have arteriopathy [El-Gharbawy et al 2011]. Ectasia of the basilar and internal carotid arteries has been noted, and may be associated with clinical signs, such as transient ischemic attacks and 3rd nerve paralysis [Sacconi et al 2010]. In addition, dilation of the ascending thoracic aorta has been noted. Echocardiography may not always be sufficient to visualize this complication [El-Gharbawy et al 2011].

Progression of skeletal muscle involvement is slower than in the infantile forms and eventually involves the diaphragm and accessory respiratory muscles [Winkel et al 2005]. Affected individuals often become wheelchair dependent because of lower limb weakness. Respiratory failure causes the major morbidity and mortality of this form of the disease [Gungor et al 2011].

Late-onset Pompe disease may present from the second to as late as the seventh decade of life with progressive proximal muscle weakness primarily affecting the lower limbs, as in a limb-girdle muscular dystrophy or polymyositis. Affected adults often describe symptoms beginning in childhood with difficulty participating in sports. Later, fatigue and difficulty with rising from a sitting position, climbing stairs, and walking prompt medical attention. In an untreated cohort of affected individuals with late-onset Pompe, the median age at diagnosis was 38 years, the median survival after diagnosis was 27 years, and the median age at death was 55 years (range 23-77 years) [Gungor et al 2011]

Evidence of advanced osteoporosis in adults with Pompe disease is accumulating; while this is likely in large part secondary to decreased ambulation, other pathologic processes cannot be overlooked [Oktenli 2000, Case et al 2007].

Respiratory failure causes the major morbidity and mortality in this form of the disease [Hagemans et al 2005]. Male gender, severity of skeletal muscle weakness, and duration of disease are all risk factors for severe respiratory insufficiency [van der Beek et al 2011].

Clinical manifestations of late-onset Pompe disease [Hirschhorn & Reuser 2001]

  • Progressive proximal muscle weakness (95%) [Winkel et al 2005]
  • Respiratory insufficiency
  • Exercise intolerance
  • Exertional dyspnea
  • Orthopnea
  • Sleep apnea
  • Hyperlordosis and/or scoliosis (childhood and juvenile onset)
  • Hepatomegaly (childhood and juvenile onset)
  • Macroglossia (childhood onset)
  • Difficulty chewing and swallowing
  • Increased respiratory infections
  • Decreased deep tendon reflexes
  • Gower sign
  • Joint contractures
  • Cardiac hypertrophy (childhood onset)

Electrophysiologic studies. Myopathy can be documented by electromyography (EMG) in all forms of Pompe disease although some muscles may appear normal. In adults, needle EMG of the paraspinal muscles may be required to demonstrate abnormalities [Hobson-Webb et al 2011].

Nerve conduction velocity (NCV) studies are normal for both motor and sensory nerves, particularly at the time of diagnosis in infantile-onset disease and in late-onset disease. However, an evolving motor axonal neuropathy has been demonstrated in a child with infantile-onset disease [Burrow et al 2010].

Genotype-Phenotype Correlations

GAA enzyme activity may correlate with age of onset and rate of progression as a "rough" general rule:

  • It is assumed that a combination of two mutated alleles that produce essentially no enzyme activity results in infantile-onset Pompe disease. Infants who have infantile Pompe with no cross-reactive material (CRIM-negative) are likely to have two null variants [Bali et al 2012].
  • Various combinations of other alleles resulting in some residual enzyme activity likely cause disease but the age of onset and progression are most likely directly proportional to the residual GAA enzyme activity.

Although a number of pathogenic variants seen in homozygosity may suggest a genotype-phenotype correlation, the existence of a number of case reports of both infantile and late-onset Pompe disease in the same family suggests strong caution in extrapolation of these observances [Hoefsloot et al 1990].

Pathogenic variants that introduce mRNA instability, such as nonsense variants, are more commonly seen in the infantile-onset form of Pompe disease as they result in nearly complete absence of GAA enzyme activity.

Missense and splicing variants may result in either complete or partial absence of GAA enzyme activity and therefore may be seen in both infantile-onset and late-onset Pompe disease [Zampieri et al 2011].

The following are observations about genotype-phenotype correlations with specific pathogenic variants (see Table 3):

  • p.Glu176ArgfsTer45 (c.525delT) is an especially common variant among the Dutch [Van der Kraan et al 1994]. It results in negligible GAA enzyme activity and must be considered one of the more severe alterations. Either in the homozygous state or in the compound heterozygous state with another severe variant, p.Glu176ArgfsTer45 predicts the infantile-onset form of Pompe disease, although the correlation is not absolute.
  • Deletion of exon 18 (p.Gly828_Asn882del; c.2482_2646del) is also a common variant, particularly among the Dutch [Van der Kraan et al 1994]. It results in negligible GAA enzyme activity and must be considered one of the more severe variants. Deletion of exon 18, either in the homozygous state or in the compound heterozygous state with another severe variant, predicts the infantile-onset form.
  • c.336-13T>G is seen in 36% to 90% of late-onset Pompe disease and is not associated with the infantile-onset form [Hermans et al 2004, Montalvo et al 2006]. The variant leads to a leaky splice site resulting in greatly diminished, but not absent, GAA enzyme activity.
  • The variant p.Asp645Glu, seen among a high proportion (≤80%) of infantile cases in Taiwan and China, is associated with a haplotype, suggesting a founder effect [Shieh & Lin 1998].
  • The variant p.Arg854Ter is frequently associated with infantile-onset Pompe disease. Found among different ethnicities, the variant has been observed in up to 60% of individuals of African descent who had a common haplotype, suggesting a founder effect [Becker et al 1998].

Table 3.

Proportion of Individuals with Select GAA Pathogenic Variants

GAA Pathogenic Variant% of Affected IndividualsReference
p.Glu176ArgfsTer4534% of Dutch casesVan der Kraan et al [1994]
9% of US casesHirschhorn & Huie [1999]
p.Gly828_Asn882del25% of infantile Dutch and Canadian casesVan der Kraan et al [1994]
5% of US casesHirschhorn & Huie [1999]
c.336-13T>G36%-90% of late-onset casesHermans et al [2004], Montalvo et al [2006]
p.Asp645GluUp to 80% of infantile Taiwanese and Chinese casesShieh & Lin [1998]
p.Arg854TerUp to 60% of individuals of African descent with a common phenotypeBecker et al [1998]


The combined incidence of all forms of Pompe disease varies, depending on ethnicity and geographic region, from 1:14,000 in African Americans to 1:100,000 in individuals of European descent (see Table 4).

Table 4.

Incidence of Pompe Disease in Different Populations

African American1:14,000Hirschhorn & Reuser [2001]
Netherlands1:40,000 combined
1:138,000 infantile onset
1:57,000 adult onset
Ausems et al [1999], Poorthuis et al [1999]
US1:40,000 combinedMartiniuk et al [1998]
South China/Taiwan1:50,000Lin et al [1987]
European descent1:100,000 infantile onset
1:60,000 late onset
Martiniuk et al [1998]
Australia1:145,000Meikle et al [1999]
Portugal1:600,000Pinto et al [2004]

The pathogenic variant p.Asp645Glu, seen among a high proportion (up to 80%) of infantile cases in Taiwan and China, is associated with a haplotype, suggesting a founder effect [Shieh & Lin 1998].

The pathogenic variant p.Arg854Ter is frequently associated with infantile-onset Pompe disease. Found among different ethnicities, the variant has been observed in up to 60% of individuals of African descent who had a common haplotype, suggesting a founder effect [Becker et al 1998].

Differential Diagnosis

Infantile-onset Pompe disease. Disorders to be considered in the differential diagnosis:

  • Spinal muscular atrophy 1 (Werdnig-Hoffman disease). Hypotonia, feeding difficulties, progressive proximal muscle weakness, and areflexia; no cardiac involvement. Caused by a defect in SMN. Inheritance is autosomal recessive.
  • Danon disease. Similar presentation of hypotonia, hypertrophic cardiomyopathy, and myopathy as a result of excessive glycogen storage caused by defects in lysosome-associated membrane protein 2 (LAMP2) [Arad et al 2005]. Inheritance is X-linked.
  • Endocardial fibroelastosis. Respiratory and feeding difficulties, cardiomegaly, and heart failure without significant muscle weakness. Etiology is often viral but familial cases with X-linked, autosomal dominant, and autosomal recessive inheritance have been described.
  • Carnitine uptake disorder. Muscle weakness and cardiomyopathy without elevated serum concentration of creatine kinase (CK). Inheritance is autosomal recessive.
  • Glycogen storage disease type IIIa (debrancher deficiency). Hypotonia, cardiomegaly, muscle weakness, and elevated serum concentration of creatine kinase with more dramatic liver involvement than typically seen in Pompe disease. Inheritance is autosomal recessive.
  • Glycogen storage disease type IV (branching enzyme deficiency). Hypotonia, cardiomegaly, muscle weakness, and elevated serum concentration of creatine kinase with more dramatic liver involvement than typically seen in Pompe disease (similar to GSD IIIa). Inheritance is autosomal recessive.
  • Idiopathic hypertrophic cardiomyopathy. Biventricular hypertrophy without hypotonia or pronounced muscle weakness
  • Myocarditis. Inflammation of the myocardium leading to cardiomegaly without hypotonia or muscle weakness
  • Mitochondrial/respiratory chain disorders. Wide variation in clinical presentation; may include hypotonia, respiratory failure, cardiomyopathy, hepatomegaly, seizures, deafness, and elevated serum concentration of creatine kinase; often distinguishable from Pompe disease by the absence of hypotonia and presence of cognitive involvement. See Mitochondrial Disorders Overview.

Late-onset Pompe disease (i.e., childhood, juvenile, and adult-onset). The early involvement of the respiratory muscles is often useful in distinguishing juvenile-onset Pompe disease from many neuromuscular disorders.

Disorders to be considered in the differential diagnosis:


Evaluations Following Initial Diagnosis

To establish the extent of disease in an individual diagnosed with glycogen storage disease type II (GSD II; Pompe disease), the following guidelines for the initial evaluation of infantile Pompe disease put forth by an expert panel from the American College of Medical Genetics [Kishnani et al 2006b] are recommended:

  • Chest radiography. In infantile-onset Pompe disease nearly all affected infants have cardiomegaly on chest x-ray [van den Hout et al 2003]. Further, evaluation of apparent lung volume reduction, areas of atelectasis, and any pulmonary fluid may be helpful in directing other therapies.

    In late-onset disease, baseline radiographic evaluation of the lungs and heart silhouette is indicated but only rarely reveals cardiomegaly.
  • Electrocardiography (ECG). In infantile Pompe disease the majority of affected infants have left ventricular hypertrophy and many have biventricular hypertrophy [van den Hout et al 2003]. Conduction disturbance is often seen.
  • Echocardiography. Typically in the infantile forms, echocardiography demonstrates hypertrophic cardiomyopathy with or without left ventricular outflow tract obstruction in the early phases of the disease process. In later stages, dilated cardiomyopathy may be seen.
  • Pulmonary assessment. Most infants have varying degrees of respiratory insufficiency. Respiratory status should be established with regard to cough, presence of wheezing or labored breathing, and/or feeding difficulties. Diaphragmatic weakness caused by excessive glycogen deposits results in mild to moderate reduction of vital capacity; however, objective assessment of pulmonary functions in infants is difficult at best. Most infants display respiratory difficulty with feeds or sleep disturbance [Kravitz et al 2005].

    Persons with late-onset disease should be evaluated for cough, wheezing, dyspnea, energy level, exercise tolerance, and fatigability. Formal pulmonary function tests in the late-onset forms show pulmonary insufficiency. An attempt to assess ventilatory capacity in the supine position can detect early ventilatory insufficiency. Pulse oximetry, respiratory rate, and venous bicarbonate and/or pCO2 should be obtained to assess for alveolar hypoventilation [van der Beek et al 2011].
  • Nutrition/feeding. Patients should be evaluated for possible feeding difficulties (e.g., facial hypotonia, macroglossia, tongue weakness, and/or poor oromotor skills) [Jones et al 2010, van Gelder et al 2012].

    Assessment of growth (i.e., height, weight, head circumference), energy intake, and feeding (including video swallow study) is appropriate.

    All infants should be evaluated for gastroesophageal reflux.
  • Audiologic. Baseline hearing evaluation including tympanometry is appropriate. See Deafness and Hereditary Hearing Loss Overview for a discussion of age-related methods of hearing evaluation. Sensorineural hearing loss is now documented in children with infantile Pompe disease, and hearing aids may be of benefit [van Capelle et al 2010].
  • Disability inventory. All patients should undergo assessment of motor skills and overall functioning to guide subsequent therapies and monitor progression of the disease.
  • Medical genetics consultation

Note: Guidelines for the evaluation of individuals with late-onset Pompe disease [Cupler et al 2012] differ in methodology from those detailed above for infantile Pompe disease, but many of the same systems (particularly pulmonary, nutrition, musculoskeletal, and disability inventory) are common to all forms of Pompe disease.

Treatment of Manifestations

Guidelines for the management of Pompe disease have been put forth by an expert panel from the American College of Medical Genetics [Kishnani et al 2006b]:

  • Cardiomyopathy. Medical intervention needs to be individualized as use of standard drugs may be contraindicated in certain stages of the disease process (see Agents/Circumstances to Avoid) [Kishnani et al 2006b].

    Enzyme replacement therapy (ERT) reduces cardiac mass to varying degrees and improves the ejection fraction, although there may be a transient decrease in the ejection fraction after the first several weeks of ERT [Levine et al 2008].
  • Arteriopathy. Treatment does not differ from that in the general population.
  • Conduction disturbances. Patients with hypertrophic cardiomyopathy are at high risk for tachyarrhythmia and sudden death [Tabarki et al 2002]. Twenty-four hour Holter monitoring is useful in characterizing the type and severity of rhythm disturbance. Management includes avoidance of stress, infection, fever, dehydration, and anesthesia. Medical therapy, if indicated, often necessitates a careful balance of ventricular function and should be undertaken by a cardiologist familiar with Pompe disease.

    ERT results in an increase of the PR interval and a decrease in the left ventricular voltage [Ansong et al 2006].
  • Muscle weakness. Physical therapy is appropriate to maintain range of motion and assist in ambulation.

    Proximal motor weakness can result in contractures of the pelvic girdle in infants and children, necessitating aggressive management including surgery [Case et al 2012]. Scoliosis is frequent, particularly in individuals with infantile or childhood onset disease [Roberts et al 2011].
  • Nutrition/feeding. Infants may need specialized diets and maximal nutrition, with some requiring gastric feedings. Persons with late-onset disease may also develop feeding concerns and are often managed on a soft diet, with a few requiring gastric or jejunal feedings. Some of these manifestations may improve on ERT [Bernstein et al 2010].
  • Respiratory insufficiency. Respiratory support including CPAP and BiPAP may be required. Inspiratory/ expiratory training has improved respiratory muscle strength in adults with late onset Pompe [Jones et al 2011].

    Macroglossia and severe respiratory insufficiency in the infantile form may necessitate tracheostomy.

Prevention of Primary Manifestations

Enzyme replacement therapy (ERT) should be initiated as soon as the diagnosis of Pompe disease is established.

The FDA approved the use of Myozyme® (alglucosidase alfa) for infantile Pompe disease in 2006. Studies on later-onset forms of Pompe disease have been completed, and Lumizyme® was approved by the FDA in 2010 for use in late-onset Pompe disease. Lumizyme is currently being studied in children with infantile onset Pompe.

Myozyme® and Lumizyme® are administered by slow IV infusion at 20-40 mg/kg/dose every two weeks.

In clinical studies, infusion reactions were observed in half of those treated with Myozyme®. The majority of treated children developed IgG antibodies to Myozyme® within the first three months of treatment. Infusion reactions appear to be more common in individuals with IgG antibodies. Development of IgE antibodies is less common but may be associated with anaphylactic reaction. Some affected individuals with high sustained IgG titers may have a poor clinical response to treatment (see Testing, Acid alpha-glucosidase protein quantitation). Most infusion-associated reactions can be modified by slowing the rate of infusion or administration of antipyretics, antihistamines, or glucocorticoids. However, anaphylaxis requiring life support measures has been reported. For these reasons – and because many individuals with Pompe disease have preexisting compromise of respiratory and cardiac function – initiation of therapy in centers equipped to provide emergency care is recommended. Transition to home infusion therapy is possible in those who have tolerated several months of infusions without clinical reaction. Home infusion therapy may have benefits to the affected individual and family, but the decision to initiate home infusions requires consideration of multiple factors, including venous access, medical stability, antibody status, and access to skilled home care providers.

Enzyme therapy in infants with known or suspected CRIM negative status requires immunomodulation very early in the treatment course, optimally before the first infusion. There are multiple immunomodulation protocols in use, most of which use rituximab with additional drugs (including mycophenylate mofetil, methotrexate, and sirolimus) [Messinger et al 2012, Elder et al 2013]. Genotyping may play a role in the rapid classification of CRIM status [Bali et al 2012]. However, clinical outcomes are poorer in infants who develop high titer anti-rhGAA antibodies, regardless of CRIM status [Banugaria et al 2011], and additional tools to identify those at risk for this outcome are needed.

In addition to drug-related reactions, children with infantile Pompe disease may have difficulty with anesthesia for procedures related to placement of venous access devices.

The relative resistance of skeletal muscle to effective glycogen depletion with administered alpha glucosidase has been observed in animals and humans, and varies with different enzyme preparations. Type II muscle fibers appear to be quite resistant to therapy. From a clinical viewpoint, the failure of most ventilator-dependent individuals to achieve independence from invasive ventilation is not surprising. Perhaps more disappointing is that five of the 18 infants treated before age six months made no meaningful gains in motor function and six of 18 became dependent on ventilatory assistance. A variety of predictors of poor prognosis were observed, including increase in muscle glycogen during therapy, high IgG titers to alpha glucosidase, and CRIM negativity.

In summary, when compared to an untreated cohort, a majority of those in whom ERT was initiated before age six months and before the need for ventilatory assistance had improved survival, improved ventilator-independent survival, reduced cardiac mass, and significantly improved acquisition of motor skills. Longer-term survivors who underwent early ERT may show sustained improvement in cardiac and motor function [Prater et al 2012]. Factors predicting poor response are incompletely understood and may only be deduced for any given individual by therapeutic trial. While the long-term prognosis is as yet unknown, available studies suggest better cognitive outcomes than had been predicted. Assessment of cognitive abilities is difficult in young children (age <5 years) with infantile Pompe disease, and typical assessment tools frequently underestimate the cognitive abilities of these children [Kishnani et al 2009, Nicolino et al 2009, Ebbink et al 2012].

In late-onset disease, the major morbidities are motor disability and respiratory insufficiency. In a randomized double-blind placebo-controlled study of 90 affected individuals age eight years and older who were ambulatory and free of invasive ventilatory support at baseline, those receiving the active agent had better preservation of motor function and forced vital capacity at the 78th week evaluation point [van der Ploeg et al 2010]. Similar findings were demonstrated in an open label trial [Strothotte et al 2010].

Prevention of Secondary Complications

Infections need to be aggressively managed.

Immunizations need to be kept current.

Patients and household members should receive annual influenza vaccinations.

Respiratory syncytial virus (RSV) prophylaxis (palivizumab) should be administered in the first two years.

Anesthesia should be used only when absolutely necessary because reduced cardiovascular return and underlying respiratory insufficiency pose significant risks.


Close follow up is indicated. Management and surveillance guidelines have been proposed by the ACMG Work Group on Management of Pompe Disease [Kishnani et al 2006b]:

  • Twice-yearly clinical review of development, clinical status, growth, and use of adaptive equipment
  • Assessment of respiratory status with each visit with regard to cough, difficulty breathing, wheezing, fatigability, and exercise tolerance:
    • Chest x-rays at regular intervals
    • Pulmonary function tests; yearly or more frequently as indicated
    • Periodic sleep evaluation, which may include regular capnography and pulse oximetry
  • Monitoring of overall musculoskeletal and functional status to guide therapies aimed at preventing or minimizing physical impairment and its complications. This may include assessment for scoliosis and bone densitometry.
  • Regular nutritional and feeding assessment
  • At least annual renal function studies to monitor for secondary complications related to cardiac and/or pulmonary impairment as well as medication effects
  • Annual cardiology evaluation in late-onset disease and as needed for infantile-onset disease:
    • Periodic echocardiography. Aortic dilatation has been detected by echocardiography in late-onset Pompe disease [El-Gharbawy et al 2011].
    • Twenty-four-hour ambulatory ECG at baseline and at regular intervals [Cook et al 2006]
    • Screening for cerebral arteriopathy with aneurysmal dilation and rupture leading to cerebral infarcts (strokes) and death, which have also been reported [Laforêt et al 2008, Sacconi et al 2010]. Screening strategies for these findings are being developed, but care teams should have a high index of suspicion for cerebral arteriopathy if an individual with late-onset Pompe disease develops unexplained stroke-like symptoms [Sacconi et al 2010].
  • Annual hearing evaluation

Agents/Circumstances to Avoid

Use of standard drugs for treatment of cardiac manifestations may be contraindicated in certain stages of the disease. The use of digoxin, ionotropes, diuretics, and afterload-reducing agents may worsen left ventricular outflow obstruction, although they may be indicated in later stages of the disease.

Hypotension and volume depletion should be avoided.

Exposure to infectious agents is to be avoided.

Evaluation of Relatives at Risk

It is appropriate to offer sibs of a proband either testing of GAA enzyme activity or molecular genetic testing (if the pathogenic variants have been identified in an affected family member) so that morbidity and mortality can be reduced by early diagnosis and treatment with ERT.

See Genetic Counseling for issues related to testing of at-risk relatives for genetic counseling purposes.

Pregnancy Management

Most individuals with infantile Pompe disease have not reproduced. Many adults with late-onset disease have reproduced. At least one woman treated with ERT during pregnancy and lactation with no adverse effects on the fetus has been reported [deVries et al 2011]. As would be expected in a woman with a myopathy and respiratory insufficiency, the growing fetus may pose additional complications to the mother’s health. Careful respiratory and cardiac surveillance should be initiated in consultation with maternal fetal medicine specialists.

Therapies Under Investigation

Gene therapy to correct the underlying enzyme defect is under investigation [Raben et al 2002, DeRuisseau et al 2009, Mah et al 2010]. A Phase I/II trial to investigate the ability of AAV- alpha glucosidase to improve ventilation is currently in progress [Byrne et al 2011].

Search for access to information on clinical studies for a wide range of diseases and conditions.


Experience with bone marrow transplantation in both humans and cattle with acid alpha-glucosidase deficiency is limited; to date, such treatment is not considered successful [Hirschhorn & Reuser 2001].

Genetic Counseling

Genetic counseling is the process of providing individuals and families with information on the nature, inheritance, and implications of genetic disorders to help them make informed medical and personal decisions. The following section deals with genetic risk assessment and the use of family history and genetic testing to clarify genetic status for family members. This section is not meant to address all personal, cultural, or ethical issues that individuals may face or to substitute for consultation with a genetics professional. —ED.

Mode of Inheritance

Glycogen storage disease type II (GSD II; Pompe disease) is inherited in an autosomal recessive manner.

Risk to Family Members

Parents of a proband

  • In most instances, the parents of a proband are heterozygotes and thus carry a single copy of a pathogenic variant in GAA.
  • Heterozygotes (carriers) are asymptomatic.

Sibs of a proband

  • At conception, each sib of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.
  • Once an at-risk sib is known to be unaffected, the chance of his/her being a carrier is 2/3.
  • Heterozygotes are asymptomatic.

Offspring of a proband

  • Children with the more common infantile form of GSD II do not reproduce, although the availability of therapy may alter this expectation through improved fitness of those individuals who respond to enzyme replacement therapy.
  • The offspring of an individual with a later-onset form of GSD II are obligate heterozygotes (carriers) for a pathogenic variant in GAA.

Other family members of a proband. Each sib of an obligate heterozygote is at a 50% risk of being a carrier.

Carrier Detection

Biochemical genetic testing. Measurement of acid alpha-glucosidase enzyme activity in skin fibroblasts, muscle, or peripheral blood leukocytes is unreliable for carrier determination because of significant overlap in residual enzyme activity levels between obligate carriers and the general (non-carrier) population.

Molecular genetic testing. Carrier testing for at-risk family members is possible if the pathogenic variants in the family have been identified.

Related Genetic Counseling Issues

See Management, Evaluation of Relatives at Risk for information on evaluating at-risk relatives for the purpose of early diagnosis and treatment.

Concordance/discordance of phenotype in family members

Family planning

  • The optimal time for determination of genetic risk, clarification of carrier status, and discussion of the availability of prenatal testing is before pregnancy.
  • It is appropriate to offer genetic counseling (including discussion of potential risks to offspring and reproductive options) to young adults who are affected, carriers, or at risk of being carriers.

DNA banking is the storage of DNA (typically extracted from white blood cells) for possible future use. Because it is likely that testing methodology and our understanding of genes, allelic variants, and diseases will improve in the future, consideration should be given to banking DNA of affected individuals.

Prenatal Testing

Molecular genetic testing. If the pathogenic variants have been identified in the family, prenatal diagnosis for pregnancies at increased risk may be available from a clinical laboratory that offers either testing for this gene or custom prenatal testing. Results of prenatal testing cannot predict the age of onset, clinical course, or degree of disability.

Biochemical genetic testing. Prenatal testing is possible by measuring GAA enzyme activity in uncultured chorionic villi or amniocytes; however, molecular genetic testing is the preferred method if the familial pathogenic variants are identified.

Preimplantation genetic diagnosis (PGD) may be an option for some families in which the pathogenic variants have been identified.


GeneReviews staff has selected the following disease-specific and/or umbrella support organizations and/or registries for the benefit of individuals with this disorder and their families. GeneReviews is not responsible for the information provided by other organizations. For information on selection criteria, click here.

  • Acid Maltase Deficiency Association (AMDA)
    PO Box 700248
    San Antonio TX 78270-0248
    Phone: 210-494-6144
    Fax: 210-490-7161
  • Association for Glycogen Storage Disease (AGSD)
    PO Box 896
    Durant IA 52747
    Phone: 563-514-4022
  • National Library of Medicine Genetics Home Reference
  • Muscular Dystrophy Association - USA (MDA)
    222 South Riverside Plaza
    Suite 1500
    Chicago IL 60606
    Phone: 800-572-1717
  • RegistryNXT!
    Phone: 888-404-4413

Molecular Genetics

Information in the Molecular Genetics and OMIM tables may differ from that elsewhere in the GeneReview: tables may contain more recent information. —ED.

Table A.

Glycogen Storage Disease Type II (Pompe Disease): Genes and Databases

Data are compiled from the following standard references: gene from HGNC; chromosome locus, locus name, critical region, complementation group from OMIM; protein from UniProt. For a description of databases (Locus Specific, HGMD) to which links are provided, click here.

Table B.

OMIM Entries for Glycogen Storage Disease Type II (Pompe Disease) (View All in OMIM)


Gene structure. GAA is approximately 20 kb in length and contains 20 exons. The cDNA is over 3.6 kb in length with 2859 nucleotides of coding sequence. For a detailed summary of gene and protein information, see Table A, Gene.

Benign allelic variants. At least 47 normal variants are known in GAA. Two polymorphic variants (and the "normal" variant) are responsible for the three known alloenzymes (GAA1, GAA2, and GAA4).

Pathogenic allelic variants. More than 150 pathogenic variants in GAA have been identified in individuals with Pompe disease. See Table A.

Nonsense variants, large and small gene rearrangements, and splicing defects have been observed. Many pathogenic variants are potentially specific to families, geographic regions, or ethnicities. Combinations of pathogenic variants that result in complete absence of GAA enzyme activity are seen more commonly in individuals with infantile-onset disease, whereas those combinations that allow partial enzyme activity typically have a later-onset presentation.

Table 5.

GAA Pathogenic Variants Discussed in This GeneReview

DNA Nucleotide Change
(Alias 1)
Protein Amino Acid ChangeReference Sequences
(IVS1 -13T>G)
(Exon 18 del)

Note on variant classification: Variants listed in the table have been provided by the authors. GeneReviews staff have not independently verified the classification of variants.

Note on nomenclature: GeneReviews follows the standard naming conventions of the Human Genome Variation Society (www​ See Quick Reference for an explanation of nomenclature.


Variant designation that does not conform to current naming conventions

Normal gene product. GAA is a lysosomal enzyme that catalyzes α-1,4- and α-1,6-glucosidic linkages at acid pH. There are seven glycosylation sites. The immature protein consists of 952 amino acids with a predicted non-glycosylated weight of 105 kd. The mature enzyme exists in either 76-kd or 70-kd form as a monomer.

Abnormal gene product. GAA pathogenic variants result in mRNA instability and/or severely truncated acid alpha-glucosidase or an enzyme with markedly decreased activity.


Published Guidelines/Consensus Statements

  1. American College of Medical Genetics. Pompe disease diagnosis and management guideline. Available online. 2006. Accessed 6-29-15.
  2. Cupler EJ, Berger KI, Leshner RT, Wolfe GI, Han JJ, Barohn RJ, Kissel JT., AANEM Consensus Committee on Late-onset Pompe Disease. Consensus treatment recommendations for late-onset Pompe disease. Muscle Nerve. 2012;45:319–33. [PMC free article: PMC3534745] [PubMed: 22173792]

Literature Cited

  1. An Y, Young SP, Hillman SL, Van Hove JL, Chen YT, Millington DS. Liquid chromatographic assay for a glucose tetrasaccharide, a putative biomarker for the diagnosis of Pompe disease. Anal Biochem. 2000;287:136–43. [PubMed: 11078593]
  2. Ansong AK, Li JS, Nozik-Grayck E, Ing R, Kravitz RM, Idriss SF, Kanter RJ, Rice H, Chen YT, Kishnani PS. Electrocardiographic response to enzyme replacement therapy for Pompe disease. Genet Med. 2006;8:297–301. [PubMed: 16702879]
  3. Arad M, Maron BJ, Gorham JM, Johnson WH Jr, Saul JP, Perez-Atayde AR, Spirito P, Wright GB, Kanter RJ, Seidman CE, Seidman JG. Glycogen storage diseases presenting as hypertrophic cardiomyopathy. N Engl J Med. 2005;352:362–72. [PubMed: 15673802]
  4. Ausems MG, Verbiest J, Hermans MP, Kroos MA, Beemer FA, Wokke JH, Sandkuijl LA, Reuser AJ, van der Ploeg AT. Frequency of glycogen storage disease type II in The Netherlands: implications for diagnosis and genetic counselling. Eur J Hum Genet. 1999;7:713–6. [PubMed: 10482961]
  5. Bali DS, Goldstein JL, Banugaria S, Dai J, Mackey J, Rehder C, Kishnani PS. Predicting cross-reactive immunological material (CRIM) status in Pompe disease using GAA mutations: lessons learned from 10 years of clinical laboratory testing experience. Am J. Med Genet C Semin Med Genet. 2012;160:40–9. [PMC free article: PMC3278076] [PubMed: 22252923]
  6. Banugaria SG, Prater SN, Ng YK, Kobori JA, Finkel RS, Ladda RL, Chen YT, Rosenberg AS, Kishnani PS. The impact of antibodies on clinical outcomes in diseases treated with therapeutic protein: lessons learned from infantile Pompe disease. Genet Med. 2011 Aug;13(8):729–36. [PMC free article: PMC3954622] [PubMed: 21637107]
  7. Becker JA, Vlach J, Raben N, Nagaraju K, Adams EM, Hermans MM, Reuser AJ, Brooks SS, Tifft CJ, Hirschhorn R, Huie ML, Nicolino M, Plotz PH. The African origin of the common mutation in African American patients with glycogen-storage disease type II. Am J Hum Genet. 1998;62:991–4. [PMC free article: PMC1377028] [PubMed: 9529346]
  8. Bernstein DL, Bialer MG, Mehta L, Desnick RJ. Pompe disease: Dramatic improvement in gastrointestinal function following enzyme replacement therapy. A report of three later-onset patients. Mol Genet Metab. 2010;101:130–3. [PubMed: 20638881]
  9. Burrow TA, Bailey LA, Kinnett DG, Hopkin RJ. Acute progression of neuromuscular findings in infantile Pompe disease. Pediatr Neurol. 2010;42:455–8. [PubMed: 20472203]
  10. Byrne BJ, Falk DJ, Pacak CA, Nayak S, Herzog RW, Elder ME, Collins SW, Conlon TJ, Clement N, Cleaver BD, Cloutier DA, Porvasnik SL, Islam S, Elmallah JK, Martin A, Smith BK, Fuller DD, Lawson LA, Mah CD. Pompe disease gene therapy. Hum Mol Genet. 2011;20:R61–8. [PMC free article: PMC3095055] [PubMed: 21518733]
  11. Case LE, Hanna R, Frush DP, Krishnamurthy V, DeArmey S, Mackey J, Boney A, Morgan C, Corzo D, Bouchard S, Weber TJ, Chen YT, Kishnani PS. Fractures in children with Pompe disease: a potential long-term complication. Pediatr Radiol. 2007;37:437–45. [PubMed: 17342521]
  12. Case LE, Beckemeyer AA, Kishnani PS. Infantile Pompe disease on ERT: update on clinical presentation, musculoskeletal management, and exercise considerations. Am J Med Genet C Semin Med Genet. 2012;160:69–79. [PubMed: 22252989]
  13. Chamoles NA, Niizawa G, Blanco M, Gaggioli D, Casentini C. Glycogen storage disease type II: enzymatic screening in dried blood spots on filter paper. Clin Chim Acta. 2004;347:97–102. [PubMed: 15313146]
  14. Chien YH, Lee NC, Thurberg BL, Chiang SC, Zhang XK, Keutzer J, Huang AC, Wu MH, Huang PH, Tsai FJ, Chen YT, Hwu WL. Pompe disease in infants: improving the prognosis by newborn screening and early treatment. Pediatrics. 2009;124:e1116–25. [PubMed: 19948615]
  15. Cook AL, Kishnani PS, Carboni MP, Kanter RJ, Chen YT, Ansong AK, Kravitz RM, Rice H, Li JS. Ambulatory electrocardiogram analysis in infants treated with recombinant human acid alpha-glucosidase enzyme replacement therapy for Pompe disease. Genet Med. 2006;8:313–7. [PubMed: 16702882]
  16. Cupler EJ, Berger KI, Leshner RT, Wolfe GI, Han JJ, Barohn RJ, Kissel JT., AANEM Consensus Committee on Late-onset Pompe Disease. Consensus treatment recommendations for late-onset Pompe disease. Muscle Nerve. 2012 Mar;45:319–33. [PMC free article: PMC3534745] [PubMed: 22173792]
  17. DeRuisseau LR, Fuller DD, Qiu K, DeRuisseau KC, Donnelly WH Jr, Mah C, Reier PJ, Byrne BJ. Neural deficits contribute to respiratory insufficiency in Pompe disease. Proc Natl Acad Sci U S A. 2009;106:9419–24. [PMC free article: PMC2695054] [PubMed: 19474295]
  18. deVries JM, Brugma JD, Ozkan L, Steegers EA, Reuser AJ, Van Doorn PA, van der Ploeg AT. First experience with enzyme replacement therapy during pregnancy and lactation in Pompe disease. Mol Genet Metab. 2011;104:552–5. [PubMed: 21967859]
  19. Ebbink BJ, Aarsen FK, van Gelder CM, van den Hout JM, Weisglas-Kuperus N, Jaeken J, Lequin MH, Arts WF, van der Ploeg AT. Cognitive outcome of patients with classic infantile Pompe disease receiving enzyme therapy. Neurology. 2012;78:1512–8. [PubMed: 22539577]
  20. Elder ME, Nayak S, Collins SW, Lawson LA, Kelley JS, Herzog RW, Modica RF, Lew J, Lawrence RM, Byrne BJ. B-cell depletion and immunomodulation before initiation of enzyme replacement therapy blocks the immune response to acid alpha-glucosidase in infantile-onset Pompe disease. J Pediatr. 2013;163:847–54. [PMC free article: PMC3981605] [PubMed: 23601496]
  21. El-Gharbawy AH, Bhat G, Murillo JE, Thurberg BL, Kampmann C, Mengel KE, Kishnani PS. Expanding the clinical spectrum of late-onset Pompe disease: dilated arteriopathy involving the thoracic aorta, a novel vascular phenotype uncovered. Mol Genet Metab. 2011;103:362–6. [PubMed: 21605996]
  22. Gungor D, de Vries JM, Hop WC, Reuser AJ, van Doorn PA, van der Ploeg AT, Hagemans ML. Survival and associated factors in 268 adults with Pompe disease prior to treatment with enzyme replacement therapy. Orphanet J Rare Dis. 2011;6:34. [PMC free article: PMC3135500] [PubMed: 21631931]
  23. Hagemans ML, Winkel LP, Van Doorn PA, Hop WJ, Loonen MC, Reuser AJ, Van der Ploeg AT. Clinical manifestation and natural course of late-onset Pompe's disease in 54 Dutch patients. Brain. 2005;128:671–7. [PubMed: 15659425]
  24. Hermans MM, van Leenen D, Kroos MA, Beesley CE, Van Der Ploeg AT, Sakuraba H, Wevers R, Kleijer W, Michelakakis H, Kirk EP, Fletcher J, Bosshard N, Basel-Vanagaite L, Besley G, Reuser AJ. Twenty-two novel mutations in the lysosomal alpha-glucosidase gene (GAA) underscore the genotype-phenotype correlation in glycogen storage disease type II. Hum Mutat. 2004;23:47–56. [PubMed: 14695532]
  25. Hirschhorn R, Huie ML. Frequency of mutations for glycogen storage disease type II in different populations: the del525T and delexon 18 mutations are not generally "common" in white populations. J Med Genet. 1999;36:85–6. [PMC free article: PMC1762954] [PubMed: 9950376]
  26. Hirschhorn R, Reuser AJ. Glycogen storage disease type II: acid alpha-glucosidase (acid maltase) deficiency. In: Scriver CR, Beaudet A, Sly WS, Valle D, eds. The Metabolic and Molecular Bases of Inherited Disease. New York, NY: McGraw-Hill; 2001:3389-420.
  27. Hobson-Webb LD, Dearmey S, Kishnani PS. The clinical and electrodiagnostic characteristics of Pompe disease with post-enzyme replacement therapy findings. Clin Neurophysiol. 2011;122:2312–7. [PubMed: 21570905]
  28. Hoefsloot LH, van der Ploeg AT, Kroos MA, Hoogeveen-Westerveld M, Oostra BA, Reuser AJ. Adult and infantile glycogenosis type II in one family, explained by allelic diversity. Am J Hum Genet. 1990;46:45–52. [PMC free article: PMC1683537] [PubMed: 2403755]
  29. Jones HN, Moss T, Edwards L, Kishnani PS. Increased inspiratory and expiratory muscle strength following respiratory muscle strength training (RMST) in two patients with late-onset Pompe disease. Mol Genet Metab. 2011;104:417–20. [PubMed: 21641843]
  30. Jones HN, Muller CW, Lin M, Banugaria SG, Case LE, Li JS, O'Grady G, Heller JH, Kishnani PS. Oropharyngeal dysphagia in infants and children with infantile pompe disease. Dysphagia. 2010;25:277–83. [PubMed: 19763689]
  31. Kallwass H, Carr C, Gerrein J, Titlow M, Pomponio R, Bali D, Dai J, Kishnani P, Skrinar A, Corzo D, Keutzer J. Rapid diagnosis of late-onset Pompe disease by fluorometric assay of alpha-glucosidase activities in dried blood spots. Mol Genet Metab. 2007;90:449–52. [PubMed: 17270480]
  32. Kamphoven JH, de Ruiter MM, Winkel LP, Van den Hout HM, Bijman J, De Zeeuw CI, Hoeve HL, Van Zanten BA, Van der Ploeg AT, Reuser AJ. Hearing loss in infantile Pompe's disease and determination of underlying pathology in the knockout mouse. Neurobiol Dis. 2004;16:14–20. [PubMed: 15207257]
  33. Kishnani PS, Corzo D, Leslie ND, Gruskin D, Van der Ploeg A, Clancy JP, Parini R, Morin G, Beck M, Bauer MS, Jokic M, Tsai CE, Tsai BW, Morgan C, O'Meara T, Richards S, Tsao EC, Mandel H. Early treatment with alglucosidase alpha prolongs long-term survival of infants with Pompe disease. Pediatr Res. 2009;66:329–35. [PMC free article: PMC3129995] [PubMed: 19542901]
  34. Kishnani PS, Goldenberg PC, DeArmey SL, Heller J, Benjamin D, Young S, Bali D, Smith SA, Li JS, Mandel H, Koeberl D, Rosenberg A, Chen YT. Cross-reactive immunologic material status affects treatment outcomes in Pompe disease infants. Mol Genet Metab. 2010;99:26–33. [PMC free article: PMC3721340] [PubMed: 19775921]
  35. Kishnani PS, Hwu WL, Mandel H, Nicolino M, Yong F, Corzo D. A retrospective, multinational, multicenter study on the natural history of infantile-onset Pompe disease. J Pediatr. 2006a;148:671–6. [PubMed: 16737883]
  36. Kishnani PS, Steiner RD, Bali D, Berger K, Byrne BJ, Case LE, Crowley JF, Downs S, Howell RR, Kravitz RM, Mackey J, Marsden D, Martins AM, Millington DS, Nicolino M, O'Grady G, Patterson MC, Rapoport DM, Slonim A, Spencer CT, Tifft CJ, Watson MS. Pompe disease diagnosis and management guideline. Genet Med. 2006b;8:267–88. [PMC free article: PMC3110959] [PubMed: 16702877]
  37. Ko TM, Hwu WL, Lin YW, Tseng LH, Hwa HL, Wang TR, Chuang SM. Molecular genetic study of Pompe disease in Chinese patients in Taiwan. Hum Mutat. 1999;13:380–4. [PubMed: 10338092]
  38. Kravitz RM, Mackey J, DeArmey S, Kishnani PS. Pulmonary function findings in patients with infantile Pompe disease. Proc Am Thorac Soc. 2005;2:A186.
  39. Labrousse P, Chien YH, Pomponio RJ, Keutzer J, Lee NC, Akmaev VR, Scholl T, Hwu WL. Genetic heterozygosity and pseudodeficiency in the Pompe disease newborn screening pilot program. Mol Genet Metab. 2010;99:379–83. [PubMed: 20080426]
  40. Laforêt P, Nicolino M, Eymard PB, Puech JP, Caillaud C, Poenaru L, Fardeau M. Juvenile and adult-onset acid maltase deficiency in France: genotype-phenotype correlation. Neurology. 2000;55:1122–8. [PubMed: 11071489]
  41. Laforêt P, Petiot P, Nicolino M, Orlikowski D, Caillaud C, Pellegrini N, Froissart R, Petitjean T, Maire I, Chabriat H, Hadrane L, Annane D, Eymard B. Dilative arteriopathy and basilar artery dolichoectasia complicating late-onset Pompe disease. Neurology. 2008;70:2063–6. [PubMed: 18505979]
  42. Levine JC, Kishnani PS, Chen YT, Herlong JR, Li JS. Cardiac remodeling after enzyme replacement therapy with acid alpha-glucosidase for infants with Pompe disease. Pediatr Cardiol. 2008;29:1033–42. [PMC free article: PMC2683920] [PubMed: 18661169]
  43. Lin CY, Hwang B, Hsiao KJ, Jin YR. Pompe's disease in Chinese and prenatal diagnosis by determination of alpha-glucosidase activity. J Inherit Metab Dis. 1987;10:11–7. [PubMed: 3106710]
  44. Mah CS, Falk DJ, Germain SA, Kelley JS, Lewis MA, Cloutier DA, DeRuisseau LR, Conlon TJ, Cresawn KO, Fraites TJ Jr, Campbell-Thompson M, Fuller DD, Byrne BJ. Gel-mediated delivery of AAV1 vectors corrects ventilatory function in Pompe mice with established disease. Mol Ther. 2010;18:502–10. [PMC free article: PMC2839425] [PubMed: 20104213]
  45. Martiniuk F, Chen A, Mack A, Arvanitopoulos E, Chen Y, Rom WN, Codd WJ, Hanna B, Alcabes P, Raben N, Plotz P. Carrier frequency for glycogen storage disease type II in New York and estimates of affected individuals born with the disease. Am J Med Genet. 1998;79:69–72. [PubMed: 9738873]
  46. McCready ME, Carson NL, Chakraborty P, Clarke JT, Callahan JW, Skomorowski MA, Chan AK, Bamforth F, Casey R, Rupar CA, Geraghty MT. Development of a clinical assay for detection of GAA mutations and characterization of the GAA mutation spectrum in a Canadian cohort of individuals with glycogen storage disease, type II. Mol Genet Metab. 2007;92:325–35. [PubMed: 17723315]
  47. Mechtler TP, Stary S, Metz TF, De Jesus VR, Greber-Platzer S, Pollak A, Herkner KR, Streubel B, Kasper DC. Neonatal screening for lysosomal storage disorders: feasibility and incidence from a nationwide study in Austria. Lancet. 2012;379:335–41. [PubMed: 22133539]
  48. Meikle PJ, Hopwood JJ, Clague AE, Carey WF. Prevalence of lysosomal storage disorders. JAMA. 1999;281:249–54. [PubMed: 9918480]
  49. Messinger YH, Mendelsohn NJ, Rhead W, Dimmock D, Hershkovitz E, Champion M, Jones SA, Olson R, White A, Wells C, Bali D, Case LE, Young SP, Rosenberg AS, Kishnani PS. Successful immune tolerance induction to enzyme replacement therapy in CRIM-negative infantile Pompe disease. Genet Med. 2012;14:135–42. [PMC free article: PMC3711224] [PubMed: 22237443]
  50. Montalvo AL, Bembi B, Donnarumma M, Filocamo M, Parenti G, Rossi M, Merlini L, Buratti E, De Filippi P, Dardis A, Stroppiano M, Ciana G, Pittis MG. Mutation profile of the GAA gene in 40 Italian patients with late onset glycogen storage disease type II. Hum Mutat. 2006;27:999–1006. [PubMed: 16917947]
  51. Nicolino M, Byrne B, Wraith JE, Leslie N, Mandel H, Freyer DR, Arnold GL, Pivnick EK, Ottinger CJ, Robinson PH, Loo JC, Smitka M, Jardine P, Tatò L, Chabrol B, McCandless S, Kimura S, Mehta L, Bali D, Skrinar A, Morgan C, Rangachari L, Corzo D, Kishnani PS. Clinical outcomes after long-term treatment with alglucosidase alfa in infants and children with advanced Pompe disease. Genet Med. 2009;11:210–9. [PubMed: 19287243]
  52. Oda E, Tanaka T, Migita O, Kosuga M, Fukushi M, Okumiya T, Osawa M, Okuyama T. Newborn screening for Pompe disease in Japan. Mol Genet Metab. 2011 Dec;104(4):560–5. [PubMed: 21963784]
  53. Oktenli C. Renal magnesium wasting, hypomagnesemic hypocalcemia, hypocalciuria and osteopenia in a patient with glycogenosis type II. Am J Nephrol. 2000;20:412–7. [PubMed: 11093001]
  54. Pinto R, Caseiro C, Lemos M, Lopes L, Fontes A, Ribeiro H, Pinto E, Silva E, Rocha S, Marcao A, Ribeiro I, Lacerda L, Ribeiro G, Amaral O, Sa Miranda MC. Prevalence of lysosomal storage diseases in Portugal. Eur J Hum Genet. 2004;12:87–92. [PubMed: 14685153]
  55. Pittis MG, Donnarumma M, Montalvo AL, Dominissini S, Kroos M, Rosano C, Stroppiano M, Bianco MG, Donati MA, Parenti G, D’Amico A, Ciana G, Di Rocco M, Reuser A, Bembi B, Filocamo M. Molecular and functional characterization of eight novel GAA mutations in Italian infants with Pompe disease. Hum Mutat. 2008;29:E27–36. [PubMed: 18429042]
  56. Pompe Disease Diagnostic Working Group. Winchester B, Bali D, Bodamer OA, Caillaud C, Christensen E, Cooper A, Cupler E, Deschauer M, Fumić K, Jackson M, Kishnani P, Lacerda L, Ledvinová J, Lugowska A, Lukacs Z, Maire I, Mandel H, Mengel E, Müller-Felber W, Piraud M, Reuser A, Rupar T, Sinigerska I, Szlago M, Verheijen F, van Diggelen OP, Wuyts B, Zakharova E, Keutzer J2008Methods for a prompt and reliable laboratory diagnosis of Pompe disease: report from an international consensus meeting. Mol Genet Metab. 93275–81. [PubMed: 18078773]
  57. Poorthuis BJ, Wevers RA, Kleijer WJ, Groener JE, de Jong JG, van Weely S, Niezen-Koning KE, van Diggelen OP. The frequency of lysosomal storage diseases in The Netherlands. Hum Genet. 1999;105:151–6. [PubMed: 10480370]
  58. Prater SN, Banugaria SG, Dearmey SM, Botha EG, Stege EM, Case LE, Jones HN, Phornphutkul C, Wang RY, Young SP, Kishnani PS. The emerging phenotype of long-term survivors with infantile Pompe disease. Genet Med. 2012;14:800–10. [PMC free article: PMC3947503] [PubMed: 22538254]
  59. Raben N, Plotz P, Byrne BJ. Acid alpha-glucosidase deficiency (glycogenosis type II, Pompe disease). Curr Mol Med. 2002;2:145–66. [PubMed: 11949932]
  60. Roberts M, Kishnani PS, van der Ploeg AT, Muller-Felber W, Merlini L, Prasad S, Case LE. The prevalence and impact of scoliosis in Pompe disease: lessons learned from the Pompe Registry. Mol Genet Metab. 2011;104:574–82. [PubMed: 21930409]
  61. Sacconi S, Bocquet JD, Chanalet S, Tanant V, Salviati L, Desnuelle C. Abnormalities of cerebral arteris are frequent in patients with late-onset Pompe disease. J Neurol. 2010;257:1730–3. [PubMed: 20559845]
  62. Shieh JJ, Lin CY. Frequent mutation in Chinese patients with infantile type of GSD II in Taiwan: evidence for a founder effect. Hum Mutat. 1998;11:306–12. [PubMed: 9554747]
  63. Slonim AE, Bulone L, Ritz S, Goldberg T, Chen A, Martiniuk F. Identification of two subtypes of infantile acid maltase deficiency. J Pediatr. 2000;137:283–5. [PubMed: 10931430]
  64. Strothotte S, Strigl-Pill N, Grunert B, Kornblum C, Eger K, Wessig C, Deschauer M, Breunig F, Glocker FX, Vielhaber S, Brejova A, Hilz M, Reiners K, Müller-Felber W, Mengel E, Spranger M, Schoser B. Enzyme replacement therapy with alglucosidase alfa in 44 patients with late-onset glycogen storage disease type 2: 12-month results of an observational clinical trial. J Neurol. 2010;257:91–7. [PubMed: 19649685]
  65. Tabarki B, Mahdhaoui A, Yacoub M, Selmi H, Mahdhaoui N, Bouraoui H, Ernez S, Jridi G, Ammar H, Essoussi AS. Familial hypertrophic cardiomyopathy associated with Wolff-Parkinson-White syndrome revealing type II glycogenosis. Arch Pediatr. 2002;9:697–700. [PubMed: 12162158]
  66. van Capelle CI, Goedegebure A, Homans NC, Hoeve HL, Reuser AJ, van der Ploeg AT. Hearing loss in Pompe disease revisited: results from a study of 24 children. J Inherit Metab Dis. 2010;33:597–602. [PMC free article: PMC2946566] [PubMed: 20596893]
  67. van der Beek NA, van Capelle CI, van der Velden-van Etten KI, Hop WC, van den Berg B, Reuser AJ, van Doorn PA, van der Ploeg AT, Stam H. Rate of progression and predictive factors for pulmonary outcome in children and adults with Pompe disease. Mol Genet Metab. 2011 Sep-Oct;104:129–36. [PubMed: 21763167]
  68. van den Hout HM, Hop W, van Diggelen OP, Smeitink JA, Smit GP, Poll-The BT, Bakker HD, Loonen MC, de Klerk JB, Reuser AJ, van der Ploeg AT. The natural course of infantile Pompe's disease: 20 original cases compared with 133 cases from the literature. Pediatrics. 2003;112:332–40. [PubMed: 12897283]
  69. Van der Kraan M, Kroos MA, Joosse M, Bijvoet AG, Verbeet MP, Kleijer WJ, Reuser AJ. Deletion of exon 18 is a frequent mutation in glycogen storage disease type II. Biochem Biophys Res Commun. 1994;203:1535–41. [PubMed: 7945303]
  70. van der Ploeg AT, Clemens PR, Corzo D, Escolar DM, Florence J, Groeneveld GJ, Herson S, Kishnani PS, Laforêt P, Lake SL, Lange DJ, Leshner RT, Mayhew JE, Morgan C, Nozaki K, Park DJ, Pestronk A, Rosenbloom B, Skrinar A, van Capelle CI, van der Beek NA, Wasserstein M, Zivkovic SA. A randomized study of alglucosidase alfa in late-onset Pompe's disease. N Engl J Med. 2010;362:1396–406. [PubMed: 20393176]
  71. van Gelder CM, van Capelle CI, Ebbink BJ, Moor-van Nugteren I, van den Hout JM, Hakkesteegt MM, van Doorn PA, de Coo IF, Reuser AJ, de Gier HH, van der Ploeg AT. Facial-muscle weakness, speech disorders and dysphagia are common in patients with classic infantile Pompe disease treated with enzyme therapy. J. Inherit Metab Dis. 2012;35:505–11. [PMC free article: PMC3319904] [PubMed: 22008944]
  72. Winkel LP, Hagemans ML, van Doorn PA, Loonen MC, Hop WJ, Reuser AJ, van der Ploeg AT. The natural course of non-classic Pompe's disease; a review of 225 published cases. J Neurol. 2005;252:875–84. [PubMed: 16133732]
  73. Young SP, Piraud M, Goldstein JL, Zhang H, Rehder C, Laforet P, Kishnani PS, Millington DS, Bashir MR, Bali DS. Assessing disease severity in Pompe disease: the roles of a urinary glucose tetrasaccharide biomarker and imaging techniques. Am J Med Genet C Semin Med Genet. 2012 Feb 15;160:50–8. [PubMed: 22252961]
  74. Young SP, Zhang H, Corzo D, Thurberg BL, Bali D, Kishnani PS, Millington DS. Long-term monitoring of patients with infantile-onset Pompe disease on enzyme replacement therapy using a urinary glucose tetrasaccharide biomarker. Genet Med. 2009 Jul;11:536–41. [PubMed: 19521244]
  75. Zampieri S, Buratti E, Dominissini S, Montalvo AL, Pittis MG, Bembi B, Dardis A. Slicing mutations in glycogen-storage disease Type II: evaluation of the full spectrum of mutations and their relation to patients’ phenotypes. Eur J Hum Genet. 2011;19:422–31. [PMC free article: PMC3060314] [PubMed: 21179066]
  76. Zhang H, Kallwass H, Young SP, Carr C, Dai J, Kishnani PS, Millington DS, Keutzer J, Chen YT, Bali D. Comparison of maltose and acarbose as inhibitors of maltase-glucoamylase activity in assaying acid alpha-glucosidase activity in dried blood spots for the diagnosis of infantile Pompe disease. Genet Med. 2006;8:302–6. [PubMed: 16702880]

Suggested Reading

  1. American Association of Neuromuscular & Electrodiagnostic Medicine. Diagnostic criteria for late-onset (childhood and adult) Pompe disease. Muscle Nerve. 2009;40:149–60. [PubMed: 19533647]
  2. Hirschhorn R, Reuser AJJ. Glycogen storage disease type II: (acid maltase) deficiency. In: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G, eds. The Online Metabolic and Molecular Bases of Inherited Disease (OMMBID). New York, NY: McGraw-Hill. Chap 135. Available online. 2013. Accessed 6-29-15.

Chapter Notes

Revision History

  • 9 May 2013 (me) Comprehensive update posted live
  • 12 August 2010 (me) Comprehensive update posted live
  • 5 August 2008 (cd) Revision: deletion/duplication testing available clinically
  • 22 April 2008 (cd) Revision: targeted mutation analysis no longer available clinically
  • 31 August 2007 (me) Review posted to live Web site
  • 8 January 2007 (btt) Original submission
Copyright © 1993-2016, University of Washington, Seattle. All rights reserved.

For more information, see the GeneReviews Copyright Notice and Usage Disclaimer.

For questions regarding permissions: ude.wu@tssamda.

Bookshelf ID: NBK1261PMID: 20301438


  • PubReader
  • Print View
  • Cite this Page
  • Disable Glossary Links

Tests in GTR by Condition

Related information

  • MedGen
    Related information in MedGen
  • OMIM
    Related OMIM records
  • PMC
    PubMed Central citations
  • PubMed
    Links to PubMed
  • Gene
    Locus Links

Similar articles in PubMed

See reviews...See all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...