Ordering Recommendation

Preferred molecular test for ATP7A-related copper transport disorders. Confirm causative variants in individuals symptomatic for Menkes disease, occipital horn syndrome, and ATP7A-related distal motor neuropathy. Determine carrier status of at-risk family members when familial variant is unknown.

Mnemonic
ATP7A FGA
Methodology

Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Performed

Varies

Reported

28-35 days

New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval

By report

Interpretive Data

Background Information for ATP7A-Related Copper Transport Disorders (ATP7A) Sequencing and Deletion/Duplication
Characteristics:
Menkes disease, occipital horn syndrome, and ATP7A-related distal motor neuropathy are disorders of copper transport due to mutations in the ATP7A gene. Individuals with Menkes disease may present in the infant period with loss of milestones, abnormal hair, lethargy, hypotonia, and seizures.  Occipital horn syndrome shares many features with Menkes disease but has a less severe neurological phenotype.
Inheritance:
X-linked.
Cause:
Pathogenic ATP7A gene mutations.
Clinical Sensitivity:
95 percent for Menkes disease and occipital horn syndrome; unknown for ATP7A-related distal motor neuropathy.
Methodology:
Bidirectional sequencing of all coding regions and intron-exon boundaries of the ATP7A gene; Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large ATP7A deletions/duplications.
Analytical Sensitivity and Specificity:
99 percent for sequencing; 99 percent and 95 percent for MLPA respectively.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations and deep intronic mutations will not be detected. The breakpoints of large deletions/duplications will not be determined. Mutations in genes other than ATP7A will not be detected.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
Hotline History
N/A
CPT Codes

81479

Components
Component Test Code* Component Chart Name LOINC
2008472 ATP7A Seq, DelDup Spcm
2008473 ATP7A Seq, DelDup Interp
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • ATP7A molecular testing
  • Copper transport disorders molecular assay
ATP7A-Related Copper Transport Disorders (ATP7A) Sequencing and Deletion/Duplication