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Prader-Willi/Angelman Syndromes
| Item | Value | ||||
|---|---|---|---|---|---|
| Approval req'd? | No | ||||
| Available Stat? | No | ||||
| Test code | PWA | ||||
| Performed by | Molecular Diagnostics | ||||
| In House Availability | Run 1x per week as needed, Wednesday or Friday, day shift only | ||||
| Method |
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| Collection Instructions | If collecting in citrate, check the expiration date on the label of the blue top vacutainer before drawing the patient. Do not collect sample in heparin. Keep sample refrigerated for overnight or longer storage. For UCSF Samples (from remote sites) Click here for sample collection instructions For NON-UCSF Samples Click here for Requisition form & Account set-up instructions. Note we only do institutional billing. |
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| Container type | Lavender top , Blue (citrate) and Yellow (ACD) tops acceptable | ||||
| Amount to Collect | 3 mL blood | ||||
| Sample type | EDTA Whole blood, Cultured amniocytes, Cultured chorionic villi | ||||
| Preferred volume | 3 mL blood | ||||
| Min. Volume | 2 mL blood | ||||
| UCSF Rejection Criteria | Samples collected in outdated blue top vacutainer. | ||||
| Processing notes | Do not centrifuge the specimen. Store at room temperature. Refrigerated samples are acceptable. | ||||
| Normal range | Negative | ||||
| Synonyms | Happy puppet syndrome; | ||||
| Stability | Blood samples are stable for up to one week. | ||||
| Turn around times | 10-14 days | ||||
| Additional information | A normal fetus inherits one copy of chromosome 15 from each parent. If the fetus inherits two paternal chromosome 15's because of uniparental disomy or carries a maternal chromosomal 15 deletion then the Angelman (Happy Puppet) Syndrome results. If the fetus inherits only the maternal chromosome as a result of paternal chromosome deletion, then the Prader-Willi Syndrome results. This assay identifies approximately 95% of Prader-Willi patients and 80% of Angelman patients; in the remaining cases of Angelman syndrome DNA sequencing of the UBE3A gene may uncover point mutations. If a mutation is detected it is recommended that the patient seek genetic counseling. |
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| CPT coding | 81331 | ||||
| LOINC code | 36915-7 | ||||
| LDT or Mod FDA? | Yes | ||||
| Last Updated | 3/13/2013 8:51:39 AM | ||||
| Entry Number | 770 |
If you have additional questions regarding this test, please call: 415-353-1667