Angelman syndrome : UBE3A Sequencing

Test Information

UBE3A sequencing is a molecular test used to identify variants in the gene associated with Angelman syndrome.

Turnaround Time

6 weeks

CPT Code(s)

81406

Cost

$1,500

Genes

Clinical Information

Angelman syndrome is characterized by severe motor and intellectual disability, absence of speech, ataxia and a characteristic open-mouthed face. Other features such as hypotonia, epilepsy and excessive laughter help in the diagnosis of the condition. Mutations in the ubiquitin-protein ligase E3A gene (UBE3A) located on chromosome 15 are known to be associated with a subset of Angelman syndrome cases. UBE3A is specifically imprinted in the brain where it is only expressed from the maternal allele. In individuals that retain the clinical diagnosis of Angelman syndrome following normal methylation studies, UBE3A sequencing studies should be given strong consideration.

Indications

Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.

Methodology

Sanger Sequencing

Detection

UBE3A mutations account for approximately 11% of patients with Angelman syndrome.

Specimen Requirements

5 to 7 ml of peripheral blood collected in an EDTA (lavender top) tube is the preferred specimen type. The minimal blood needed for reliable DNA isolation is 3 ml. Extracted DNA, dried blood spots, and saliva are also accepted for this test.

Transport Instructions

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal Testing Information

Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.

Have Questions Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Sanger Sequencing
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