Prader-Willi/Angelman Syndrome, Molecular Analysis, Varies
Use
This test is useful for the confirmation of diagnosis in patients suspected of having either Prader-Willi syndrome (PWS) or Angelman syndrome (AS) based on clinical assessment or previous laboratory analysis. It is also used for prenatal diagnosis in families at risk for PWS or AS. This test is the preferred first-tier test for diagnosis of Angelman syndrome (AS) and Prader-Willi syndrome (PWS).
Special Instructions
All prenatal specimens must be accompanied by a maternal blood specimen. The test may require routine chromosomal microarray analysis if diagnosis is uncertain. Consultation with the laboratory is required for all prenatal testing. A previous bone marrow transplant from an allogenic donor will interfere with testing.
Limitations
Rare variants may lead to false-negative or false-positive results. Certain conditions may cause diagnostic confusion, like improper specimen collection and handling. Methylation status cannot be assessed on chorionic villus specimens. Some rare cases of Prader-Willi syndrome or Angelman syndrome result from subtle balanced translocations that may not be detected by this assay. A negative molecular test result does not rule out the diagnosis, as point alterations may not be detected.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 35466-2
- 50397-9
- 82939-0
- 69047-9
- 42349-1
- 31208-2
- 18771-6
Result Turnaround Time
10-14 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
Not provided
Container
Lavender top (EDTA) or yellow top (ACD)
Collection Instructions
Invert several times to mix blood. Send whole blood specimen in original tube. Do not aliquot.
Patient Preparation
A previous bone marrow transplant from an allogenic donor will interfere with testing.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 4 days |
| Frozen | 4 days |