Angelman Syndrome - RRPL
Discipline
Genetics and Genomics
Overview
Description
Ordering recommendations
- This test should be used as the first-line diagnostic test in a child with a suspected clinical diagnosis of Angelman Syndrome (AS) as it provides information regarding methylation, regardless of the underlying mechanism. This does not rule out sequence variants in UBE3A and further testing is warranted for high suspicion with negative results from this test.
Ordering requirements
- Use RRPL Molecular Diagnostics Requisitions
- This test has been pre-approved for select medical specialties as indicated (Physician Approval to Order)
- Other physicians may inquire about getting their patient tested through the Genetics Resource Centre process
- Rush/urgent cases must be indicated on the requisition along with an e-mail to RRPLMolecularGenetics@saskhealthauthority.ca
- If this test will impact an ongoing pregnancy, also fax an urgent referral to the division of medical genetics: 306-655-1736 (otherwise see Genetic Resource Centre process)
Alias
- AS, ANGS, UBE3A
Specimen Information
Specimen types accepted
- Whole blood: Lavender (EDTA) 4.0 mL
Specimen collection container
- Preferred collection container: Lavender (EDTA) 4.0 mL
- Alternative collection container: Microcollection - EDTA
Required volume
- Optimal volume: 8 mL
- Minimum volume: 0.5 mL
- Pediatric volume: 0.5 – 3 mL
EDTA tubes should be completely full, 2/3 full at minimum, testing may be affected by partial draw
- For patients over 20 kg: 2 EDTA tubes each containing 3.0 mL of blood
- For patients up to 20 kg: 2 EDTA tubes each containing 2.0 mL of blood
- For neonates: 1 EDTA containing a minimum of 0.5 mL of blood
Transport and stability
- Specimen specific storage and transport instructions (ex. Frozen, ship on ice, temperature specification)
- Room temperature: if being shipped on same day of collection (preferred).
- Refrigerated: If shipping is delayed
Performance
Methodology
- Purpose of test (brief): Prader-Willi/Angelman test is intended to confirm a potential cause for and clinical diagnosis of Prader-Willi syndrome (PWS), Angelman syndrome (AS), and 15q11 duplication syndrome. In rare cases, this product can also be used for carrier testing of at-risk family members. Detects copy number changes and determines methylation status. Does not distinguish between imprinting center pathogenic variants and UPD.
- How testing is performed: 15q11 methylation sensitive MLPA
- Clinical result interpretations: Interpretation provided on report.
Specimen retention time
For more information, please visit the RRPL Requisitions and Completion Aids page.
Last Updated: March 28, 2024