Angelman Syndrome and Prader-Willi Syndrome by Methylation-Specific MLPA
Also known as: AS-PWS DD
Use
The test is used for the initial diagnosis of Angelman syndrome (AS) and Prader-Willi syndrome (PWS). AS is characterized by developmental delays, seizures, and a distinctive behavioral phenotype, while PWS features neonatal hypotonia, hyperphagia, obesity, and behavioral challenges. This test targets the methylation patterns in the AS/PWS critical region of chromosome 15q11.2-q13 to detect anomalies linked to these syndromes.
Special Instructions
Not provided.
Limitations
The test will not detect disease mechanisms causing AS that do not alter methylation patterns. It cannot detect increased copy number of 15q11.2-q13 or determine the parent of origin for duplications. It cannot distinguish between UPD or an imprinting defect for PWS or AS. Mosaicism is not assessed, and interpretive challenges may arise if an allogeneic stem cell transplantation has occurred. Diagnostic testing on chorionic villus samples is not recommended due to potentially undeveloped methylation patterns.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 66746-9 - Specimen type
- 41117-3 - AS+PWS gene Mut Anl Bld/T
Result Turnaround Time
12-14 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
1 mL
Container
Lavender (EDTA) or pink (K2EDTA) tube
Causes for Rejection
Transfused whole blood, severely hemolyzed whole blood, heparinized whole blood, frozen whole blood.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 week |
| Refrigerated | 1 month |
| Frozen | unacceptable |
Other tests from different labs that may be relevant