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Alpha-N-acetylgalactosaminidase deficiency type 2

MedGen UID:
324539
Concept ID:
C1836522
Disease or Syndrome
Synonyms: ALPHA-N-ACETYLGALACTOSAMINIDASE DEFICIENCY, TYPE II; Kanzaki disease; NAGA DEFICIENCY, TYPE II; SCHINDLER DISEASE, TYPE II
SNOMED CT: Alpha-N-acetylgalactosaminidase deficiency type 2 (880065001); Schindler disease type 2 (880065001); NAGA (alpha-N-acetylgalactosaminidase) deficiency type 2 (880065001)
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
141025
Concept ID:
C0441748
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele).
 
Gene (location): NAGA (22q13.2)
 
Monarch Initiative: MONDO:0012222
OMIM®: 609242
Orphanet: ORPHA79280

Definition

Alpha-N-acetylgalactosaminidase (NAGA) deficiency is a very rare lysosomal storage disorder with atypical features. It is clinically heterogeneous with 3 main phenotypes: type I is an infantile-onset neuroaxonal dystrophy (609241); type II, also known as Kanzaki disease, is an adult-onset disorder characterized by angiokeratoma corporis diffusum and mild intellectual impairment; and type III is an intermediate disorder (see 609241) with mild to moderate neurologic manifestations (Desnick and Schindler, 2001). [from OMIM]

Additional description

From MedlinePlus Genetics
Alpha-N-acetylgalactosaminidase deficiency type II is the least severe form. Type II is typically diagnosed in adulthood. Affected individuals may have mild cognitive impairment and hearing loss caused by abnormalities of the inner ear (sensorineural hearing loss). They may also experience a loss of sensation or muscle weakness in the extremities (peripheral neuropathy). Clusters of enlarged blood vessels that form small, dark red spots on the skin (angiokeratomas) are a characteristic feature of alpha-N-acetylgalactosaminidase deficiency type II.

Type III is the intermediate form of alpha-N-acetylgalactosaminidase deficiency. People with type III may show a variety of signs and symptoms, including developmental, speech, and language delays; seizures that begin in infancy; and features of autism spectrum disorder that appear in childhood. Autism spectrum disorder is characterized by impaired communication and socialization skills. People with type III may also have skeletal signs and symptoms, such as pain in the lower back, hips, and knees. Wear on the cartilage (disks) and bones of the neck (cervical spondylosis) and a cyst-like collection of cerebrospinal fluid that forms in the spinal cord (syringohydromyelia) have also been reported.

Alpha-N-acetylgalactosaminidase deficiency, also known as Schindler disease, is an inherited disorder that can affect the development of the nervous system. People with alpha-N-acetylgalactosaminidase deficiency often have distinctive facial features that can be described as "coarse" and tooth abnormalities such as widely-spaced teeth and missing teeth (hypodontia).

Type I is the most severe form of this condition. Babies with alpha-N-acetylgalactosaminidase deficiency type I appear healthy at birth. However, by late infancy, these babies typically have trouble meeting normal developmental milestones. By the age of 2 years, individuals with type I begin to lose skills that they had already acquired (developmental regression). Individuals with type I often experience weak muscle tone (hypotonia), vision and hearing loss, and seizures. During early childhood, children with type I typically lose awareness of their surroundings and eventually become unresponsive.

The three types of alpha-N-acetylgalactosaminidase deficiency differ in the severity of their signs and symptoms and the age at which they first appear. The signs and symptoms of alpha-N-acetylgalactosaminidase deficiency can vary, even among members of the same family.   https://medlineplus.gov/genetics/condition/alpha-n-acetylgalactosaminidase-deficiency

Clinical features

From HPO
Aminoaciduria
MedGen UID:
116067
Concept ID:
C0238621
Disease or Syndrome
An increased concentration of an amino acid in the urine.
Increased urinary O-linked sialopeptides
MedGen UID:
373111
Concept ID:
C1836533
Finding
Excretion of peptides conjugated to sialic acid in the urine.
Sensorineural hearing loss disorder
MedGen UID:
9164
Concept ID:
C0018784
Disease or Syndrome
A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.
Vertigo
MedGen UID:
53006
Concept ID:
C0042571
Sign or Symptom
An abnormal sensation of spinning while the body is actually stationary.
Mild intellectual disability
MedGen UID:
10044
Concept ID:
C0026106
Mental or Behavioral Dysfunction
Mild intellectual disability (ID) is defined as a type of ID characterized by mildly sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 50-69.
Cerebral atrophy
MedGen UID:
116012
Concept ID:
C0235946
Disease or Syndrome
Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum.
Cognitive impairment
MedGen UID:
90932
Concept ID:
C0338656
Mental or Behavioral Dysfunction
Abnormal cognition is characterized by deficits in thinking, reasoning, or remembering.
Peripheral axonal neuropathy
MedGen UID:
266071
Concept ID:
C1263857
Disease or Syndrome
An abnormality characterized by disruption of the normal functioning of peripheral axons.
Abnormal posterior periventricular white matter morphology
MedGen UID:
373109
Concept ID:
C1836525
Finding
An anomaly of the white matter of the brain localized in the region posterior to the cerebral ventricles.
Distal sensory impairment of all modalities
MedGen UID:
322937
Concept ID:
C1836527
Finding
Reduced ability to sense pain, temperature, touch, vibration stimuli in the distal regions of the extremities.
Axonal degeneration
MedGen UID:
332464
Concept ID:
C1837496
Finding
Distal sensory impairment
MedGen UID:
335722
Concept ID:
C1847584
Finding
An abnormal reduction in sensation in the distal portions of the extremities.
Lacunar stroke
MedGen UID:
465269
Concept ID:
C3178801
Disease or Syndrome
A stroke related to a small infarct (2-20 mm in diameter) in the deep cerebral white matter, basal ganglia, or pons, that is presumed to result from the occlusion of a single small perforating artery supplying the subcortical areas of the brain.
Distal muscle weakness
MedGen UID:
140883
Concept ID:
C0427065
Finding
Reduced strength of the musculature of the distal extremities.
Lymphedema
MedGen UID:
6155
Concept ID:
C0024236
Disease or Syndrome
Localized fluid retention and tissue swelling caused by a compromised lymphatic system.
Depressed nasal bridge
MedGen UID:
373112
Concept ID:
C1836542
Finding
Posterior positioning of the nasal root in relation to the overall facial profile for age.
Thick lower lip vermilion
MedGen UID:
326567
Concept ID:
C1839739
Finding
Increased thickness of the lower lip, leading to a prominent appearance of the lower lip. The height of the vermilion of the lower lip in the midline is more than 2 SD above the mean. Alternatively, an apparently increased height of the vermilion of the lower lip in the frontal view (subjective).
Coarse facial features
MedGen UID:
335284
Concept ID:
C1845847
Finding
Absence of fine and sharp appearance of brows, nose, lips, mouth, and chin, usually because of rounded and heavy features or thickened skin with or without thickening of subcutaneous and bony tissues.
Fabry disease
MedGen UID:
8083
Concept ID:
C0002986
Disease or Syndrome
Fabry disease is the most common of the lysosomal storage disorders and results from deficient activity of the enzyme alpha-galactosidase A (a-Gal A), leading to progressive lysosomal deposition of globotriaosylceramide and its derivatives in cells throughout the body. The classic form, occurring in males with less than 1% a-Gal A enzyme activity, usually has its onset in childhood or adolescence with periodic crises of severe pain in the extremities (acroparesthesia), the appearance of vascular cutaneous lesions (angiokeratomas), sweating abnormalities (anhidrosis, hypohidrosis, and rarely hyperhidrosis), characteristic corneal and lenticular opacities, and proteinuria. Gradual deterioration of kidney function to end-stage kidney disease (ESKD) usually occurs in men in the third to fifth decade. In middle age, most males successfully treated for ESKD develop cardiac and/or cerebrovascular disease, a major cause of morbidity and mortality. Heterozygous females typically have milder symptoms at a later age of onset than males. Rarely, females may be relatively asymptomatic throughout a normal life span or may have symptoms as severe as those observed in males with the classic phenotype. In contrast, late-onset forms occur in males with greater than 1% a-Gal A activity. Clinical manifestations include cardiac disease, which usually presents in the sixth to eighth decade with left ventricular hypertrophy, cardiomyopathy, arrhythmia, and proteinuria; kidney failure, associated with ESKD but without the skin lesions or pain; or cerebrovascular disease presenting as stroke or transient ischemic attack.
Petechiae
MedGen UID:
10680
Concept ID:
C0031256
Finding
Petechiae are pinpoint-sized reddish/purple spots, resembling a rash, that appear just under the skin or a mucous membrane when capillaries have ruptured and some superficial bleeding into the skin has happened. This term refers to an abnormally increased susceptibility to developing petechiae.
Dry skin
MedGen UID:
56250
Concept ID:
C0151908
Sign or Symptom
Skin characterized by the lack of natural or normal moisture.
Hyperkeratosis
MedGen UID:
209030
Concept ID:
C0870082
Disease or Syndrome
Hyperkeratosis is a histopathological term defining a thickened stratum corneum and may be present in many different skin conditions, with many possible overlaps. Hyperkeratosis refers to the increased thickness of the stratum corneum, the outer layer of the skin. Hyperkeratosis is subclassified as orthokeratotic or parakeratotic. Orthokeratotic hyperkeratosis refers to the thickening of the keratin layer with preserved keratinocyte maturation, while parakeratotic hyperkeratosis shows retained nuclei as a sign of delayed maturation of keratinocytes.
Lip telangiectasia
MedGen UID:
347522
Concept ID:
C1857697
Finding
Telangiectasia (that is, the presence of small dilated superficial blood vessels) of the lips.
Telangiectasia of the oral mucosa
MedGen UID:
870436
Concept ID:
C4024882
Anatomical Abnormality
Telangiectasia (that is, the presence of small dilated superficial blood vessels) of the oral mucosa.
Tortuosity of conjunctival vessels
MedGen UID:
344487
Concept ID:
C1855391
Finding
The presence of an increased number of twists and turns of the conjunctival blood vessels.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVAlpha-N-acetylgalactosaminidase deficiency type 2
Follow this link to review classifications for Alpha-N-acetylgalactosaminidase deficiency type 2 in Orphanet.

Recent clinical studies

Diagnosis

Mohamed FE, Al Sorkhy M, Ghattas MA, Al-Zaabi N, Al-Shamsi A, Almansoori TM, Al-Gazali L, Al-Dirbashi OY, Al-Jasmi F, Ali BR
J Mol Neurosci 2020 Jan;70(1):45-55. Epub 2019 Aug 29 doi: 10.1007/s12031-019-01398-6. PMID: 31468281
Sarbu M, Zhu F, Peter-Katalinić J, Clemmer DE, Zamfir AD
Rapid Commun Mass Spectrom 2015 Nov 15;29(21):1929-37. doi: 10.1002/rcm.7288. PMID: 26443390
Sarbu M, Robu A, Peter-Katalinić J, Zamfir AD
Carbohydr Res 2014 Oct 29;398:90-100. Epub 2014 Sep 6 doi: 10.1016/j.carres.2014.08.014. PMID: 25243357
Casado M, Altimira L, Montero R, Castejón E, Nascimento A, Pérez-Dueñas B, Ormazabal A, Artuch R
Anal Bioanal Chem 2014 Jul;406(18):4337-43. Epub 2014 May 2 doi: 10.1007/s00216-014-7832-6. PMID: 24788891

Clinical prediction guides

Casado M, Altimira L, Montero R, Castejón E, Nascimento A, Pérez-Dueñas B, Ormazabal A, Artuch R
Anal Bioanal Chem 2014 Jul;406(18):4337-43. Epub 2014 May 2 doi: 10.1007/s00216-014-7832-6. PMID: 24788891

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