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Summary
Disease characteristics. Menkes disease, occipital horn syndrome (OHS), and ATP7A-related distal motor neuropathy (DMN) are disorders of copper transport caused by mutations in the copper-transporting ATPase gene (ATP7A).
Infants with classic Menkes disease appear healthy until age two to three months, when loss of developmental milestones, hypotonia, seizures, and failure to thrive occur. The diagnosis is usually suspected when infants exhibit typical neurologic changes and concomitant characteristic changes of the hair (short, sparse, coarse, twisted, and often lightly pigmented). Temperature instability and hypoglycemia may be present in the neonatal period. Death usually occurs by age three years.
Occipital horn syndrome is characterized by "occipital horns," distinctive wedge-shaped calcifications at the sites of attachment of the trapezius muscle and the sternocleidomastoid muscle to the occipital bone. Occipital horns may be clinically palpable or observed on skull radiographs. Individuals with OHS also have lax skin and joints, bladder diverticula, inguinal hernias, and vascular tortuosity. Intellect is normal or slightly reduced.
ATP7A-related distal motor neuropathy, an adult-onset disorder resembling Charcot-Marie-Tooth disease, shares none of the clinical or biochemical abnormalities characteristic of Menkes disease or OHS.
Diagnosis/testing. Menkes disease and OHS are characterized by low concentrations of copper in some tissues as a result of impaired intestinal copper absorption, accumulation of copper in other tissues, and reduced activity of copper-dependent enzymes such as dopamine beta hydroxylase (DBH) and lysyl oxidase. While serum copper concentration and serum ceruloplasmin concentration are low in Menkes disease and OHS, they are normal in ATP7A-related DMN. Molecular genetic testing of ATP7A is clinically available.
Management. Treatment of manifestations: Classic Menkes disease: gastrostomy tube placement to manage caloric intake; surgery for bladder diverticulae.
Prevention of primary manifestations: Subcutaneous injections of copper histidine or copper chloride before age ten days normalizes developmental outcome in some children and improves the neurologic outcome in others.
Prevention of secondary complications: Antibiotic prophylaxis may prevent bladder infection.
Genetic counseling. The ATP7A-related copper transport disorders are inherited in an X-linked manner. Approximately one third of affected males have no family history of Menkes disease/OHS/DMN. If the mother is a carrier, the risk of transmitting the ATP7A mutation is 50% in each pregnancy: a male who inherits the mutation will be affected with the disorder present in his brother; females who inherit the mutation will be carriers and will not be affected. Males with OHS or ATP7A-related DMN will pass the disease-causing mutation to all of their daughters and none of their sons. Individuals with classic Menkes disease do not reproduce. Carrier testing for at-risk female relatives and prenatal testing for pregnancies at increased risk are possible if the disease-causing ATP7A mutation has been identified in a family. Prenatal testing for Menkes disease is also possible by copper transport studies in cultured chorionic villus cells or amniocytes.
Diagnosis
Clinical Diagnosis
Menkes disease is suspected in males who develop hypotonia, failure to thrive, and seizures between age six and ten weeks.
Shortly thereafter, hair changes become manifest: the scalp and (usually) eyebrow hair is short, sparse, coarse, twisted, and often lightly pigmented (white, silver, or gray). The hair is shorter and thinner on the sides and back of the head. The hair can be reminiscent of steel wool cleaning pads. Light microscopic hair analysis reveals pili torti (hair shafts twisting 180°), trichoclasis (transverse fracture of the hair shaft), and trichoptilosis (longitudinal splitting of the hair shaft). Because of the flattening of the normal cylindric structure, the periodicity of the twisting in pili torti is different from that found in naturally curly hair.
Specific clinical features include:
- Distinctive facial features (jowly appearance with sagging cheeks)
- Pectus excavatum (midline depression in the bony thorax)
- Skin laxity particularly on the nape of the neck and trunk
- Umbilical or inguinal herniae
- Hypotonia, neurodevelopmental delays, and failure to thrive, typically manifest by age three to six months
Occipital horn syndrome is suspected in males with:
- Occipital horns: distinctive wedge-shaped calcifications at the site of attachment of the trapezius muscle and the sternocleidomastoid muscle to the occipital bone. These calcifications may be clinically palpable or observed on skull radiographs.
- Lax skin and joints
- Bladder diverticula
- Inguinal herniae
- Vascular tortuosity
- Dysautonomia (chronic diarrhea, orthostatic hypotension)
- Mild cognitive deficits
ATP7A-related distal motor neuropathy, an adult-onset distal motor neuropathy resembling Charcot-Marie-Tooth disease, shares none of the clinical or biochemical abnormalities characteristic of Menkes disease or occipital horn syndrome.
It is characterized by:
- Progressive distal motor neuropathy with minimal or no sensory symptoms
- Distal muscle weakness and atrophy in feet and hands with occasional pes cavus foot deformities
- Deep tendon reflexes vary from normal to diminished, with frequently absent ankle reflexes
- Nerve conduction tests: reduced compound motor amplitudes with generally normal conduction velocities with positive waves and fibrillations on EMG
Testing
For laboratories offering biochemical testing, see
.
Serum concentration of copper and ceruloplasmin. Individuals with classic Menkes disease or occipital horn syndrome have low serum copper concentration and low serum ceruloplasmin concentration (see Table 1).
Table 1. Serum Copper and Serum Ceruloplasmin Concentration in Menkes Disease, Occipital Horn Syndrome, and ATP7A-Related Distal Motor Neuropathy
| Serum Concentration | Menkes Disease 1 | Occipital Horn Syndrome | ATP7A-Related Distal Motor Neuropathy | Normal |
|---|---|---|---|---|
| Copper | 0-55 µg/dL | 40-80 µg/dL | 80-100 µg/dl | 70-150 µg/dL; (birth - 6 mos: 20-70 µg/dL) |
| Ceruloplasmin | 10-160 mg/L | 110-240 mg/L | 240-310 mg/L | 200-450 mg/L; (birth - 6 mos: 50-220 mg/L) |
1. Diagnosis of Menkes disease using these studies alone in children under age six months is problematic given the normally low serum concentration in all children at this age.
Copper transport studies in cultured fibroblasts. Impaired cellular copper exodus is demonstrated by increased cellular copper retention in pulse-chase experiments with radiolabelled copper in Menkes disease and OHS
Plasma and CSF catecholamine analysis. Plasma catechol concentrations are distinctively abnormal at all ages in Menkes disease and OHS (but normal in ATP7A-related distal motor neuropathy); such testing is clinically available. Abnormal levels reflect partial deficiency of DBH (dopamine-beta-hydroxylase), a copper-dependent enzyme critical for catecholamine biosynthesis
Carrier females. Biochemical testing is generally unreliable for carrier detection because of overlap with normal ranges.
Molecular Genetic Testing
Gene. ATP7A is the only gene known to be associated with Menkes disease, occipital horn syndrome, and ATP7A-related distal motor neuropathy.
Clinical testing
- Sequence analysis or mutation scanning. Direct sequence analysis of the ATP7A coding region and flanking intron sequences detects:
- In males: point mutations and small intra-exonic deletions and insertions (~80% of mutations) [Tumer et al 2003];
- In females: point mutations and small intra-exonic deletions and insertions.
Note: Deletion of an exon, multiple exons, or an entire ATP7A allele in a female could be masked in sequence analysis or mutation scanning by her normal allele.
- Deletion/duplication analysis. Testing by a variety of methods can be used to detect deletion of an ATP7A exon, multiple exons, or the whole gene in about 15% of males and females [Tumer et al 2003].
Table 2. Summary of Molecular Genetic Testing Used in Menkes Disease and Occipital Horn Syndrome
| Gene Symbol | Test Method | Mutations Detected | Mutation Detection Frequency by Test Method 1 | Test Availability | |
|---|---|---|---|---|---|
| Affected Males | Carrier Females | ||||
| ATP7A | Sequence analysis or mutation scanning 2,3 | Sequence variants 4 | ~80% | ~80% | Clinical![]() |
| Small intra-exonic deletions and insertions | |||||
| Deletion / duplication analysis 5 | Deletion of an exon(s) or of the whole gene | ~15% 6 | ~15% | ||
Test Availability refers to availability in the GeneTests™ Laboratory Directory. GeneReviews designates a molecular genetic test as clinically available only if the test is listed in the GeneTests™ Laboratory Directory by either a US CLIA-licensed laboratory or a non-US clinical laboratory. GeneTests does not verify laboratory-submitted information or warrant any aspect of a laboratory's licensure or performance. Clinicians must communicate directly with the laboratories to verify information.
1. The ability of the test method used to detect a mutation that is present in the indicated gene
2. Sequence analysis and mutation scanning of the entire gene can have similar detection frequencies; however, detection rates for mutation scanning may vary considerably between laboratories based on specific protocol used.
3. Sequence analysis of genomic DNA cannot detect deletion of an exon(s) or a whole gene on the X chromosome in carrier females.
4. Examples of mutations detected by sequence analysis may include small intragenic deletions/insertions and missense, nonsense, and splice site mutations; typically, exonic or whole-gene deletions/duplications are not detected.
5. Testing that identifies 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. See CMA.
6. Deletion/duplication analysis can be used to confirm a putative exon/multiexon or whole-gene deletion in males after failure to amplify by PCR in sequence analysis or mutation scanning.
Interpretation of test results. For issues to consider in interpretation of sequence analysis results, click here.
Testing Strategy
To confirm the diagnosis in a proband
- Serum concentration of copper and ceruloplasmin for Menkes disease and OHS only.
- Plasma and CSF catecholamine analysis for Menkes disease and OHS only
- Molecular genetic testing for all three phenotypes
- Copper transport studies in cultured fibroblasts for Menkes disease only
Note: This method is reserved for urgent prenatal testing when a family’s mutation is unknown; however, this situation should become exceedingly rare with increased availability and efficiency of molecular genetic testing.
Carrier testing for at-risk relatives requires prior identification of the disease-causing mutation in the family.
Note: (1) Female carriers are heterozygotes for these X-linked disorders and are typically asymptomatic, in some instances due to favorably skewed X-inactivation [Desai et al 2011]. In theory, unfavorably skewed X-inactivation in some carrier females could be associated with neurologic or other clinical findings related to the disorders. (2) Identification of female carriers requires either (a) prior identification of the disease-causing mutation in the family or, (b) if an affected male is not available for testing, molecular genetic testing first by sequence analysis, and then, if no mutation is identified, by methods to detect gross structural abnormalities.
Prenatal diagnosis and preimplantation genetic diagnosis (PGD) for at-risk pregnancies require prior identification of the disease-causing mutation in the family.
Note: It is the policy of GeneReviews to include in GeneReviews™ chapters any clinical uses of testing available from laboratories listed in the GeneTests™ Laboratory Directory; inclusion does not necessarily reflect the endorsement of such uses by the author(s), editor(s), or reviewer(s).
Genetically Related (Allelic) Disorders
Menkes disease, occipital horn syndrome, and ATP7A-related distal motor neuropathy are the only phenotypes currently known to be associated with mutations in ATP7A.
Clinical Description
Natural History
The clinical spectrum of ATP7A-related copper transport disorders ranges from classic Menkes disease at the severe end to occipital horn syndrome (OHS) to distal motor neuropathy (DMN). Classic Menkes disease is characterized by neurodegeneration and failure to thrive commencing at ages two to three months. The age at diagnosis is usually about eight months. In contrast, OHS presents in early to middle childhood and is characterized predominantly by connective tissue abnormalities. ATP7A-related distal motor neuropathy is adult-in onset, resembles Charcot-Marie-Tooth disease, and shares none of the clinical abnormalities characteristic of Menkes disease or OHS.
Classic Menkes disease. Infants appear healthy until age two to three months, when loss of developmental milestones, hypotonia, seizures, and failure to thrive occur. Classic Menkes disease is usually first suspected when infants exhibit typical neurologic changes and concomitant characteristic changes of the hair (short, sparse, coarse, twisted, often lightly pigmented) and jowly appearance of the face.
Autonomic dysfunction including temperature instability and hypoglycemia may be present in the neonatal period; some infants have syncope and diarrhea.
Vascular tortuosity, bladder diverticulae that can result in bladder outlet obstruction, and gastric polyps are common.
Without early treatment with parenteral copper, and sometimes even with such treatment, classic Menkes disease progresses to severe neurodegeneration and death between ages seven months and 3.5 years. Subdural hematomas and cerebrovascular accidents are common. Respiratory failure, often precipitated by pneumonia, is a common cause of death.
Imaging
- MRI shows defective myelination, atrophy with ventriculomegaly, and vascular tortuosity.
- MR angiography reveals a "corkscrew" appearance of cerebral vessels.
- Radiographs show Wormian bones and metaphyseal spurring and may show rib fractures.
Mild Menkes disease. A few affected individuals in whom motor and cognitive development is better than in classic Menkes disease have been described. Individuals with mild Menkes disease may walk independently and talk. Weakness, ataxia, tremor, and head bobbing are characteristic neurologic findings. Seizures, if present, commence in mid-late childhood; intellectual disability is mild. Connective tissue problems may be more prominent than in classic Menkes disease. Pili torti are present.
Occipital horn syndrome (OHS or X-linked cutis laxa). Intelligence is normal or slightly reduced. The only apparent neurologic abnormalities of OHS are dysautonomia and subtle cognitive deficits. Affected individuals typically live to at least mid-adulthood. Fertility is unknown.
ATP7A-related distal motor neuropathy. The age of onset ranges from five to 60 years, and is typically during the second or thirrd decade of life [Kennerson et al 2010]. Findings include atrophy and weakness of distal muscles in hands and feet, foot drop with steppage gait, sometimes mild proximal weakness in the legs, with normal deep tendon reflexes or absent ankle reflexes. Sensory examination may be normal or show mild loss in the fingers and toes. The index case of the largest family reported had slow progression over 25 years, requiring ankle foot orthotics at age 38 years [Kennerson et al 2009].
Females. Carriers typically do not have symptoms. About one-half of obligate Menkes and OHS carriers show regions of pili torti [Moore & Howell 1985].
Evaluation of obligate female carriers in ATP7A-related distal motor neuropathy families has been limited to date. In the family of Kennerson et al [2009] the clinical neurologic examinations and motor nerve conduction studies of the females proven to be heterozygous were normal.
Genotype-Phenotype Correlations
The amount of residual ATPase enzyme activity correlates with phenotype Menkes disease, OHS, and ATP7A-related distal motor neuropathy and with response to early copper treatment in Menkes disease [Kaler et al 2008].
Tumer et al [2003] observed that with rare exceptions gross gene deletions result in classic Menkes disease with death in early childhood.
Milder variants of Menkes disease and OHS are often associated with splice junction mutations that alter, but do not eliminate, proper RNA splicing (i.e., "leaky" splice junction defects).
This newly discovered allelic variant associated with ATP7A-related distal motor neuropathy involves unique missense mutations within or near the luminal surface of the protein which may be relevant to the abnormal intracellular trafficking shown for these defects and to the mechanism of this form of motor neuron disease [Kennerson et al 2010].
Intrafamilial phenotypic variability is occasionally observed in Menkes disease [Kaler et al 1994, Borm et al 2004, Donsante et al 2007]. Differences noted among affected individuals from two families with ATP7A-related distal motor neuropathy included degree of weakness, atrophy, and sensory loss [Kennerson et al 2010].
Prevalence
The incidence of Menkes disease and its variants is estimated at one in 100,000 births.
Differential Diagnosis
For current information on availability of genetic testing for disorders included in this section, see GeneTests Laboratory Directory. —ED.
Menkes disease. The differential diagnosis of Menkes disease includes other infantile-onset neurodevelopmental syndromes including:
- Aminoacidurias
- Mitochondrial myopathies (see Mitochondrial Diseases Overview)
Occipital horn syndrome (OHS). The differential diagnosis of OHS includes:
- FBLN5-related cutis laxa, inherited in an autosomal recessive manner and caused by mutations in the gene encoding fibulin-5
- ELN-related cutis laxa, inherited in an autosomal dominant manner and caused by mutations in the gene encoding elastin.
The differential diagnosis of ATP7A-related distal motor neuropathy includes other forms of Charcot-Marie-Tooth disease.
Management
Evaluations Following Initial Diagnosis
To establish the extent of disease in a male diagnosed with Menkes disease, the following evaluations are recommended:
- Developmental assessment
- Evaluation of feeding and nutrition
- Assessment of bladder function
To establish the extent of disease in a male diagnosed with OHS, evaluations for the following are recommended:
- Bladder diverticula
- Inguinal herniae
- Vascular tortuosity
- Dysautonomia (chronic diarrhea, orthostatic hypotension). Note: Some medical centers have clinical autonomic testing laboratories.
- Mild cognitive deficits
To establish the extent of disease in a male diagnosed with ATP7A-related distal motor neuropathy (DMN), the following evaluations are recommended:
- Neurologic examination
- EMG with nerve conduction studies
Treatment of Manifestations
Menkes disease
- Gastrostomy tube placement to manage caloric intake and general nutrition in some males with classic Menkes disease
- Surgery for bladder diverticulae that occur in classic Menkes disease
- Developmental intervention
ATP7A-related distal motor neuropathy
- Physical therapy (strength and stretching exercises)
- Occupational therapy
- Ankle foot orthotics
Prevention of Primary Manifestations
Menkes disease. In classic Menkes disease, treatment with subcutaneous injections of copper histidine or copper chloride before ten days of age normalizes developmental outcome in some individuals and improves the neurologic outcome in others [Kaler et al 2008, Kaler et al 2010].
Note: Despite very early copper histidine treatment, some infants show no significant improvement relative to the natural history of untreated Menkes disease [Kaler et al 1995, Kaler et al 2008].
To maintain serum copper concentration in the normal range (70-150 µg/dL), the suggested dose of copper chloride is:
- For children under age one year: 250 µg administered subcutaneously twice a day
- For children older than age one year: 250 µg administered subcutaneously once a day
Prevention of Secondary Complications
Antibiotic prophylaxis may be necessary to prevent bladder infection.
Surveillance
Monitor serum copper and ceruloplasmin levels to avoid supranormal levels.
Evaluation of Relatives at Risk
See Genetic Counseling for issues related to testing of at-risk relatives for genetic counseling purposes.
Therapies Under Investigation
Results of a clinical trial of copper histidine for early diagnosed Menkes disease therapy were published [Kaler et al 2008].
Search ClinicalTrials.gov for access to information on clinical studies for a wide range of diseases and conditions.
Other
Therapies proven to be ineffective include vitamin C.
Genetics clinics, staffed by genetics professionals, provide information for individuals and families regarding the natural history, treatment, mode of inheritance, and genetic risks to other family members as well as information about available consumer-oriented resources. See the GeneTests Clinic Directory.
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. To find a genetics or prenatal diagnosis clinic, see the GeneTests Clinic Directory.
Mode of Inheritance
Menkes disease, occipital horn syndrome, and ATP7A-related distal motor neuropathy are inherited in an X-linked recessive manner.
Risk to Family Members
Parents of a proband
- In a family with more than one affected individual, the mother of an affected male is an obligate carrier.
- If a woman has more than one affected son and the disease-causing mutation cannot be detected in DNA extracted from leukocytes, she has germline mosaicism.
- Approximately one third of affected males are simplex cases (i.e., they have no known family history of Menkes disease/OHS/DMN). Several possibilities regarding the carrier status of the mothers of simplex male cases need to be considered:
- The mother is not a carrier and the affected male has a de novo disease-causing mutation. About one third of males have Menkes disease/OHS/DMN as the result of a de novo mutation.
- The mother is a carrier of a de novo disease-causing mutation that occurred:
- As a germline mutation that was present at the time of her conception, is present in every cell of her body, and is detectable in DNA extracted from her leukocytes
OR - As a somatic mutation, i.e., a change that occurred very early in embryogenesis, resulting in somatic mosaicism, in which the mutation is present in only a percentage of cells and may not be detectable in leukocyte DNA
OR - As a mutation that is present only in her ovaries; termed "germline mosaicism," in which not all germ cells have the mutation, and in which the mutation is not detectable in DNA from leukocytes. While germline mosaicism is a theoretical possibility in Menkes disease/OHS/DMN, it has not been unequivocally demonstrated.
Sibs of a proband
- The risk to sibs depends on the carrier status of the mother.
- If the disease-causing mutation cannot be detected in DNA extracted from the leukocytes of the mother, the risk to sibs is low but greater than that of the general population because of the possibility of germline mosaicism.
Offspring of a proband
- Males with OHS and ATP7A-related DMN pass the disease-causing mutation to all of their daughters and none of their sons.
- Males with classic Menkes disease have not reproduced to date.
Other family members. The proband's maternal female relatives may be at risk of being carriers, and their offspring, depending on their gender, may be at risk of being carriers or being affected.
Carrier Detection
Carrier testing of at-risk female relatives is possible if the mutation has been identified in the family. See Molecular Genetic Testing.
Biochemical testing is generally unreliable for carrier detection because of overlap with normal ranges.
Related Genetic Counseling Issues
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 or at risk.
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, mutations, and diseases will improve in the future, consideration should be given to banking DNA of affected individuals. See
for a list of laboratories offering DNA banking.
Prenatal Testing
Prenatal testing is possible for pregnancies at increased risk if the ATP7A mutation has been identified in a family member or if biochemical studies have confirmed the diagnosis in a family member. The usual procedure is to determine fetal sex by performing chromosome analysis on fetal cells obtained by chorionic villus sampling (CVS) at approximately ten to 12 weeks' gestation or by amniocentesis usually performed at approximately 15 to 18 weeks' gestation. If the karyotype is 46,XY, prenatal testing can be done in one of two ways:
- If the disease-causing mutation has been identified in a family member, DNA from fetal cells can be analyzed for the known disease-causing mutation.
- Copper transport studies can be performed in pregnancies at increased risk for Menkes disease; however, molecular genetic testing is the preferred test method for prenatal diagnosis.
Note: Gestational age is expressed as menstrual weeks calculated either from the first day of the last normal menstrual period or by ultrasound measurements.
Preimplantation genetic diagnosis (PGD) may be available for families in which the disease-causing mutation has been identified. For laboratories offering PGD, see
.
Note: It is the policy of GeneReviews to include in GeneReviews™ chapters any clinical uses of testing available from laboratories listed in the GeneTests™ Laboratory Directory; inclusion does not necessarily reflect the endorsement of such uses by the author(s), editor(s), or reviewer(s).
Resources
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.
- Corporation for Menkes Disease5720 Buckfield CourtFort Wayne IN 46804Phone: 219-436-0137Email: j1@home.com
- Medline Plus
- National Institute of Neurological Disorders and Stroke (NINDS)PO Box 5801Bethesda MD 20824Phone: 800-352-9424 (toll-free); 301-496-5751; 301-468-5981 (TTY)
- National Library of Medicine Genetics Home Reference
- NCBI Genes and Disease
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. ATP7A-Related Copper Transport Disorders: Genes and Databases
| Gene Symbol | Chromosomal Locus | Protein Name | Locus Specific | HGMD |
|---|---|---|---|---|
| ATP7A | Xq21 | Copper-transporting ATPase 1 | ATP7A @ LOVD | ATP7A |
Table B. OMIM Entries for ATP7A-Related Copper Transport Disorders (View All in OMIM)
Normal allelic variants. ATP7A contains 23 exons spanning 150 kb genomic DNA. The coding sequence is 4.5 kb. Rarely, alternatively spliced transcripts (of uncertain significance) are discerned in normal tissues. There are some known normal allelic variants.
Pathologic allelic variants. Pathologic allelic variants tend to be family-specific (unique). A range of mutation types have been identified, including: small insertions and deletions (35%), nonsense mutations (20%), splicing abnormalities (15%), missense mutations (8%), and large deletions or rearrangements (20%) [Culotta & Gitlin 2001].
The ATP7A-related distal motor neuropathy involves unique missense mutations within or near the luminal surface of the protein [Kennerson et al 2010], which may be relevant to the abnormal intracellular trafficking shown for these defects, and the mechanism of this form of motor neuron disease.
Normal gene product. The protein encoded by ATP7A, a P-type ATPase, transports copper across cellular membranes and is critical for copper homeostasis.
Abnormal gene product. ATP7A mutations may result in a gene product with no copper transport capability (associated with a severe phenotype) or reduced quantity of normally functioning gene product (associated with a milder phenotype).
References
Medical Genetic Searches: A specialized PubMed search designed for clinicians that is located on the PubMed Clinical Queries page 
Literature Cited
- Borm B, Moller LB, Hausser I, Emeis M, Baerlocher K, Horn N, Rossi R. Variable clinical expression of an identical mutation in the ATP7A gene for Menkes disease/occipital horn syndrome in three affected males in a single family. J Pediatr. 2004;145:119–21. [PubMed: 15238919]
- Culotta VC, Gitlin JD. Disorders of copper transport. In: Scriver CR, Beaudet AL, Sly WS, Valle D, eds. The Metabolic and Molecular Bases of Inherited Disease. 8 ed. Vol 2. New York: McGraw-Hill; 2001:3105-26.
- Desai V, Donsante A, Swoboda KJ, Martensen M, Thompson J, Kaler SG. Favorably skewed X-inactivation accounts for neurological sparing in female carriers of Menkes disease. Clin Genet. 2011;79:176–82. [PMC free article: PMC3099248] [PubMed: 20497190]
- Donsante A, Tang JR, Godwin SC, Holmes CS, Goldstein DS, Bassuk A, Kaler SG. Differences in ATP7A gene expression underlie intra-familial variability in Menkes disease/occipital horn syndrome. J Med Genet. 2007;44:492–7. [PMC free article: PMC2597922] [PubMed: 17496194]
- Kaler SG, Buist NR, Holmes CS, Goldstein DS, Miller RC, Gahl WA. Early copper therapy in classic Menkes disease patients with a novel splicing mutation. Ann Neurol. 1995;38:921–8. [PubMed: 8526465]
- Kaler SG, Gallo LK, Proud VK, Percy AK, Mark Y, Segal NA, Goldstein DS, Holmes CS, Gahl WA. Occipital horn syndrome and a mild Menkes phenotype associated with splice site mutations at the MNK locus. Nat Genet. 1994;8:195–202. [PubMed: 7842019]
- Kaler SG, Holmes CS, Goldstein DS, Tang JR, Godwin SC, Donsante A, Liew CJ, Sato S, Patronas N. Neonatal diagnosis and treatment of Menkes disease. N Engl J Med. 2008;358:605–14. [PMC free article: PMC3477514] [PubMed: 18256395]
- Kaler SG, Liew CJ, Donsante A, Hicks JD, Sato S, Greenfield JC. Molecular correlates of epilepsy in early diagnosed and treated Menkes disease. J Inher Metab Dis. 2010;33:583–9. [PMC free article: PMC3113468] [PubMed: 20652413]
- Kennerson M, Nicholson G, Kowalski B, Krajewski K, El-Khechen D, Feely S, Chu S, Shy M, Garbern J. X-linked distal hereditary motor neuropathy maps to the DSMAX locus on chromosome Xq13.1-q21. Neurology. 2009;72:246–52. [PubMed: 19153371]
- Kennerson ML, Nicholson GA, Kaler SG, Kowalski B, Mercer JF, Tang J, Llanos RM, Chu S, Takata RI, Speck-Martins CE, Baets J, Almeida-Souza L, Fischer D, Timmerman V, Taylor PE, Scherer SS, Ferguson TA, Bird TD, De Jonghe P, Feely SM, Shy ME, Garbern JY. Missense mutations in the copper transporter gene ATP7A cause X-linked distal hereditary motor neuropathy. Am J Hum Genet. 2010;86:343–52. [PMC free article: PMC2833394] [PubMed: 20170900]
- Moore CM, Howell RR. Ectodermal manifestations in Menkes disease. Clin Genet. 1985;28:532–40. [PubMed: 4075564]
- Tumer Z, Birk Moller L, Horn N. Screening of 383 unrelated patients affected with Menkes disease and finding of 57 gross deletions in ATP7A. Hum Mutat. 2003;22:457–64. [PubMed: 14635105]
Suggested Reading
- Chelly J, Tumer Z, Tonnesen T, Petterson A, Ishikawa-Brush Y, Tommerup N, Horn N, Monaco AP. Isolation of a candidate gene for Menkes disease that encodes a potential heavy metal binding protein. Nat Genet. 1993;3:14–9. [PubMed: 8490646]
- Danks DM, Cartwright E, Stevens BJ, Townley RR. Menkes' kinky hair disease: further definition of the defect in copper transport. Science. 1973;179:1140–2. [PubMed: 4120259]
- Donsante A, Johnson P, Jansen LA, Kaler SG. Somatic mosaicism in Menkes disease suggests choroid plexus-mediated copper transport to the developing brain. Am J Med Genet A. 2010;152A:2529–34. [PMC free article: PMC3117432] [PubMed: 20799318]
- Ganguly A, Rock MJ, Prockop DJ. Conformation-sensitive gel electrophoresis for rapid detection of single-base differences in double-stranded PCR products and DNA fragments: evidence for solvent-induced bends in DNA heteroduplexes. Proc Natl Acad Sci U S A. 1993;90:10325–9. [PMC free article: PMC47767] [PubMed: 8234293]
- Gasch AT, Caruso RC, Kaler SG, Kaiser-Kupfer M. Menkes' syndrome: ophthalmic findings. Ophthalmology. 2002;109:1477–83. [PubMed: 12153799]
- Kaler SG. Menkes disease. Adv Pediatr. 1994;41:263–304. [PubMed: 7992686]
- Kaler SG, Das S, Levinson B, Goldstein DS, Holmes CS, Patronas NJ, Packman S, Gahl WA. Successful early copper therapy in Menkes disease associated with a mutant transcript containing a small in-frame deletion. Biochem Mol Med. 1996;57:37–46. [PubMed: 8812725]
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Chapter Notes
Revision History
- 14 October 2010 (me) Comprehensive update posted live
- 13 July 2005 (me) Comprehensive update posted to live Web site
- 9 May 2003 (me) Review posted to live Web site
- 27 November 2002 (sk) Original submission
Note: Pursuant to 17 USC Section 105 of the United States Copyright Act, the GeneReview ‘ATP7A-Related Copper Transport Disorders’ is in the public domain in the United States of America.
- A novel frameshift mutation in exon 23 of ATP7A (MNK) results in occipital horn syndrome and not in Menkes disease.[Am J Hum Genet. 2001]A novel frameshift mutation in exon 23 of ATP7A (MNK) results in occipital horn syndrome and not in Menkes disease.Dagenais SLAdam AN, Innis JW, Glover TW, . Am J Hum Genet. 2001 Aug; 69(2):420-7. Epub 2001 Jun 26.
- Review ATP7A-related copper transport diseases-emerging concepts and future trends.[Nat Rev Neurol. 2011]Review ATP7A-related copper transport diseases-emerging concepts and future trends.Kaler SG. Nat Rev Neurol. 2011 Jan; 7(1):15-29.
- Distinctive Menkes disease variant with occipital horns: delineation of natural history and clinical phenotype.[Am J Med Genet. 1996]Distinctive Menkes disease variant with occipital horns: delineation of natural history and clinical phenotype.Proud VKMussell HG, Kaler SG, Young DW, Percy AK, . Am J Med Genet. 1996 Oct 2; 65(1):44-51.
- In utero copper treatment for Menkes disease associated with a severe ATP7A mutation.[Mol Genet Metab. 2012]In utero copper treatment for Menkes disease associated with a severe ATP7A mutation.Haddad MRMacri CJ, Holmes CS, Goldstein DS, Jacobson BE, Centeno JA, Popek EJ, Gahl WA, Kaler SG, . Mol Genet Metab. 2012 Sep; 107(1-2):222-8. Epub 2012 May 18.
- Review [From gene to disease; Menkes disease: copper deficiency due to an ATP7A-gene defect].[Ned Tijdschr Geneeskd. 2007]Review [From gene to disease; Menkes disease: copper deficiency due to an ATP7A-gene defect].Aldenhoven MKlomp LW, van Hasselt PM, de Koning TJ, Visser G, . Ned Tijdschr Geneeskd. 2007 Oct 13; 151(41):2266-70.
- ATP7A-Related Copper Transport Disorders - GeneReviews™ATP7A-Related Copper Transport Disorders - GeneReviews™Bookself
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