Methylation Specific PCR, SNRPN gene, 15q
| WSLH Department: | Cytogenetics |
| WSLH Test Code: | 889 |
| Availability: | Monday-Friday 7:45 AM - 4:30 PM, Saturday 7:45 AM - 12:00 PM |
| Turn-around Time: | Approximately 10-14 days, with an average of 6 days. (Reports are issued Monday-Friday 7:45 AM - 4:30 PM) |
| Recommended Uses: | Diagnosis of Prader Willi Syndrome or Angelman Syndrome |
| Contraindications: | |
| Additional Tests Performed: |
| Patient Preparations: | |
| Specimen Requirements: | 4 ml (preferred) - 2 ml (minimum) whole blood collected in EDTA vacuum type tube |
| Specimen Handling & Transport: | Store and transport specimens at room temperature (may transport with coolant during hot weather, >85 degrees F). DO NOT FREEZE. The laboratory must receive specimens within 24 hours of collection. |
| Collection Kit/Container: | |
| Collection Instructions: | Draw blood using aseptic techniques into a sterile EDTA vacuum type tube(s). Invert tube(s) to mix. If using larger tubes, draw to full volume to avoid over-treatment with anticoagulant. |
| Unacceptable Conditions: | Blood that is clotted or hemolyzed is not acceptable. Blood must not be frozen. Plasma and serum are not acceptable. |
| Requisition Form: |
Cytogenetics Lab Genetic Diagnosis Form #131
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| Required Information: | Laboratory regulations require the following minimum information to be provided on the requisition form for a specimen to be accepted for testing: Patient name or unique identifier; date and time of collection, patient date of birth and sex, specimen type/site of collection, test request(s), reason for referral, clinician name and UPIN/NPI, and address for reporting results. Please be certain that name/identifier on the form matches that on the specimen label. |
| Results Include: | Negative: Maternal and paternal methylation patterns detected. Prader-Willi Syndrome positive: Paternal methylation pattern not detected. Angelman Syndrome positive: Maternal methylation pattern not detected. |
| Limitations: | This analysis detects abnormal methylation patterns due to deletions, uniparental disomy (UPD), or imprinting defects, but cannot distinguish between the three. This assay cannot detect mosaicism. Nucleotide variation in primer binding sites can lead to allele dropout. |
| Additional Tests Recommended: | If an abnormal result is obtained, chromosomal microarray analysis (CMA) or FISH (fluorescence in situ hybridization) analysis is recommended to distinguish between deletion and uniparental disomy/abnormal methylation. |
| Additional Comments: |
| Methodology: | Methylation Specific PCR; Differential methylation at the CpG island of the SNRPN gene is detected using a bisulfite conversion of methylated DNA, followed by PCR amplification with allele specific primers and detection by agarose gel electrophoresis. This distinguishes the methylated (maternal) and unmethylated (paternal) copies of the gene. |
| Includes: | DNA isolation and quantification. PCR amplification of bisulfite converted DNA for the detection of differential (parent of origin) methylation within the CpG island of the small nuclear ribonucleoprotein-associated polypeptide N (SNRPN). |
| CPT Code: | 81331 |
| Price: | For pricing information, please call 608-262-0402. |