Test Code: 1466

Brunner Syndrome: MAOA Gene Sequencing
Test Code: 1466
Turnaround time: 5 weeks

CONDITION DESCRIPTION

Mutations in the MAOA gene result in the X-linked disorder Brunner syndrome, or monoamine oxidase deficiency, which is characterized in part by severe impulsive behavior and mild nondysmorphic intellectual disability. MAOA encodes for monoamine oxidase A, an enzyme that degrades amine neurotransmitters such as dopamine, norepinephrine, and serotonin.

For patients with suspected Brunner syndrome, 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:
• OMIM 309850: Monoamine Oxidase A; MAOA
• OMIM 300615: Brunner Syndrome
• Gunter et al. Behavioral Genetics in Antisocial Spectrum Disorders and Psychopathy: A Review of the Recent Literature. (2010). Behav. Sci. Law 28: 148-173.

GENES
MAOA

INDICATIONS
This test is indicated for:

  • Confirmation of a clinical diagnosis of Brunner syndrome.
  • Carrier testing in adults with a family history of Brunner syndrome.

METHODOLOGY

PCR amplification of 15 exons contained in the MAOA gene is performed on the patient’s genomic DNA. Direct sequencing of amplification products is performed in both forward and reverse directions, using automated fluorescence dideoxy sequencing methods. The patient’s gene sequences are then compared to a normal reference sequence. Sequence variations are classified as mutations, benign variants unrelated to disease, or variations of unknown clinical significance. Variants of unknown clinical significance may require further studies of the patient and/or family members. This assay does not interrogate the promoter region, deep intronic regions, or other regulatory elements, and does not detect large deletions.

DETECTION

Clinical Sensitivity: Unknown. Mutations in the promoter region, some mutations in the introns and other regulatory element mutations cannot be detected by this analysis. Large deletions will not be detected by this analysis. Results of molecular analysis should be interpreted in the context of the patient’s biochemical phenotype.

Analytical Sensitivity: ~99%

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
Submit copies of diagnostic biochemical test results with the sample, if appropriate.
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

  • Deletion/duplication analysis of the MAOA gene by CGH array is available for those individuals in whom sequence analysis is negative.
  • Custom diagnostic mutation analysis (test code: 6875) is available to family members if mutations are identified by targeted mutation testing or sequencing analysis.