Cytogenetics Test Requisition | Specimen Information | Billing Information | Contact Us | CPT Codes | Print
Test Details
CHROMOSOMAL LOCUS: 15q11.2
PSEUDONYMS: 15q11.2 deletion, UBE3A gene deletion
TURNAROUND TIME: 7 to 10 days
TESTING METHODOLOGY: Fluorescence in situ hybridization
Indications for Use:
- Patients suspected of having Angelman syndrome on the basis of clinical findings such as facial dysmorphology, gait ataxia, frequent laughter, failure to learn speech, microcephaly, or severe developmental delay.
- Patients with a positive DNA methylation test for Angelman syndrome.
Specimen Requirements
- Collect: 3-5 mL peripheral blood in sodium heparin (green) for children and adults; 1-2 mL peripheral blood in sodium heparin (green) for newborns
- Minimum Collection: 1 mL for newborns; 2 mL for children and adults
- Transport: peripheral blood in sodium heparin (green) at 20-25°C
- Stability: Ambient: 24 hours; Refrigerated: 72 hours; Frozen: unacceptable
- Unacceptable Conditions: Frozen or clotted specimens; specimens in anticoagulants other than sodium heparin
A Cytogenetics Laboratory Test Requisition must accompany the specimen. Contact the Cytogenetics Laboratory at 918-502-1722 to obtain further information.
Interpretive Data
Test Summary: Test can detect microdeletions of the D15S10/UBE3A locus in 15q11.2. Approximately 70% of patients with Angelman syndrome have deletions of D15S10/UBE3A.
Methods: A dual-color FISH analysis performed on metaphase cells using probes for the UBE3A in 15q11.2 and for the D15Z1 and the PML control loci; analysis of 10 metaphase cells and 20 interphase cells.
Test Limitations: The test does not detect other causes of Angelman syndrome such as paternal uniparental disomy, imprinting defects or mutations of the UBE3A gene.
Related Tests
Angelman Syndrome, DNA methylation
Additional Resources
OMIM - www.omim.org/entry/105830
Genetics Home Reference - http://ghr.nlm.nih.gov/condition/angelman-syndrome
GeneReviews - www.ncbi.nlm.nih.gov/books/NBK1144/