Test Code: 3277

Adenosine Monophosphate Deaminase (AMPD) Deficiency, Erythrocytic: AMPD3 Gene Deletion/Duplication
Test Code: 3277
Turnaround time: 3 weeks

Adenosine monophosphate deaminase (AMPD) is found in muscle, liver, and erythrocytes. The AMPD3 gene (11p15.4) encodes the AMPD found in erythrocytes. Individuals with two mutations in their AMPD3 gene are healthy and have no hematologic disorders. Their ATP levels were approximately 150% higher in the AMPD deficient red cells when compared with control cells. Additionally, degradation of the adenine nucleotide was slower in the deficient red cells when compared with control cells. AMPD deficiency is inherited in an autosomal recessive pattern.

For patients with suspected AMPD deficiency, sequence analysis is recommended as the first step in mutation identification. For patients in whom mutations are not identified by full gene sequencing, deletion/duplication analysis is appropriate.

References:
• Yamada et al. (1994). Human Molecular Genetics, 3:331-334.
• OMIM #612874: AMPD deficiency, erythrocytic
• OMIM #102772: AMPD3 gene

GENES
AMPD3

INDICATIONS
This test is indicated for:

  • Confirmation of a clinical diagnosis of adenosine monophosphate deaminase deficiency, erythrocytic in an individual in whom sequence analysis was negative.
  • Carrier testing in adults with a family history of adenosine monophosphate deaminase deficiency, erythrocytic in whom sequence analysis was negative.

METHODOLOGY

DNA isolated from peripheral blood is hybridized to a CGH array to detect deletions and duplications. The targeted CGH array has overlapping probes which cover the entire genomic region.

Please note that a “backbone” of probes across the entire genome are included on the array for analytical and quality control purposes. Rarely, off- target copy number variants causative of disease may be identified that may or may not be related to the patient’s phenotype. Only known pathogenic off-target copy number variants will be reported. Off-target copy number variants of unknown clinical significance will not be reported.

DETECTION

Detection is limited to duplications and deletions. The CGH array will not detect point or intronic mutations. Results of molecular analysis must be interpreted in the context of the patient’s clinical and/or biochemical phenotype.

SPECIMEN REQUIREMENTS

Submit only 1 of the following specimen types
* Preferred specimen type: Whole Blood

Type: Whole Blood
Specimen Requirements:
In EDTA (purple top) or ACD (yellow top) tube: Infants (2 years): 3-5 ml
Older Children & Adults: 5-10 ml

Specimen Collection and Shipping: Refrigerate until time of shipment. Ship sample within 5 days of collection at room temperature with overnight delivery.

Type: Saliva
Specimen Requirements:
OrageneTM Saliva Collection kit (available through CEN4GEN) used according to manufacturer instructions.

Specimen Collection and Shipping: Store sample at room temperature. Ship sample within 5 days of collection at room temperature with overnight delivery.

SPECIAL INSTRUCTIONS
Sequence analysis is required before deletion/duplication analysis by targeted CGH array. If sequencing is performed by another third party provider, please submit a copy of the sequencing report with the test requisition.

RELATED TESTS

  • Sequence analysis of the AMPD3 gene is available and is required before deletion/duplication analysis.
  • Sequence and deletion/duplication analysis for the AMPD1 gene are available.
  • Custom diagnostic mutation analysis (test code: 6875) is available to family members if mutations are identified by targeted mutation testing or sequencing analysis.