Rett Syndrome - RRPL
Discipline
Genetics and Genomics
Overview
Description
Ordering recommendations
- This test should be used as the first-line diagnostic test in a girl with a suspected clinical diagnosis of Rett syndrome. Restricted to testing females only.
Ordering requirements
- 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
- MECP2
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
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Purpose of test (brief): The diagnosis of a Rett syndrome (MECP2 disorder) is established by molecular genetic testing in a female proband with suggestive findings and a heterozygous MECP2 pathogenic variant.
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How testing is performed: Sanger sequencing and MLPA. Sanger sequencing: Analysis of all coding regions (MECP2a and MECP3b isoforms). MLPA: Detects deletions and duplications.
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Clinical result interpretations: Interpretation provided on report.
Specimen retention time
- For more information, please visit the RRPL Requisitions and Completion Aids page.
Last Updated: April 2, 2024