Collect whole blood in a purple top (EDTA) tube (preferred). Extracted DNA is acceptable.
5ml whole blood or 1 ug DNA
Refrigerate sample until shipment. Send the sample at room temperature with overnight delivery for receipt Monday through Friday within 24 hours of collection.
Whole blood can be refrigerated until shipment.
Heparinized specimens, severely hemolyzed specimens, frozen, clotted or possibly commingled specimens, blood in non-sterile or leaky containers, mislabeled or inappropriately labeled specimens.
Do not heat, freeze or centrifuge blood before shipment. Refrigerate sample until shipment.
Mon - Fri 9:00am to 4:00pm
Angelman syndrome (AS) is a neurobehavioral disorder with an incidence of 1 in 20,000 Angelman syndrome (AS) is characterized by severe developmental delay or mental retardation, severe speech impairment, gait ataxia and/or tremulousness of the limbs, and a unique behavior with an inappropriately happy demeanor that includes frequent laughing, smiling, and excitability. In addition, microcephaly and seizures are common.
Angelman syndrome is caused by the absence of the maternally derived region (15q11-15q13) on chromosome 15. The disorder is genetically heterogeneous. Approximately 70% of patients have a large deletion on maternal chromosome 15q11-q13; 1% of patients have rarer structural chromosome anomalies; about 7% of patients have paternal uni-parental disomy (UPD) for chromosome 15; 3% of patients carry an Imprinting Centre (IC) mutation; and 11 % have a UBE3A gene mutation. Most of the mutations identified in the UBE3A gene are truncating or frameshift mutations in the Hect domain of the protein. Missense mutations outside the hect domain are related to a milder phenotype. About 10% of AS patients have no detectable mutation.
Sequence analysis of the mutation previously identified in a family member will be performed.
The analytical sensitivity is close to 100% for point mutations by DNA sequencing.
Prenatal testing is available to individuals who are confirmed carriers of point mutations in the UBE3A gene. Please contact the laboratory director to discuss appropriate testing prior to collecting a prenatal specimen.
Test results with interpretation will be mailed and/or faxed to the referring physician or send out lab following completion of the test. Additional reports will be provided as requested.
The clinical utility of these assays is to confirm a clinical diagnosis; facilitate proper clinical management, and to alert parents to possible recurrence risk.
Whole blood in EDTA purple top tubes is the preferred sample. High molecular weight genomic DNA is acceptable. Cheek epithelial cells or other samples containing DNA may be acceptable. Contact the laboratory for specific instructions regarding such samples before sending the sample.
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