Indications For Prader-Willi Syndrome (PWS) / Angelman Syndrome
Diagnostic criteria for PWS may include: hypotonia, failure to thrive, rapid weight gain between 12 months and 6 years, characteristic facial features, hypogonadism and mild to moderate mental retardation. Diagnostic criteria for Angelman Syndrome may include feeding problems in the first few months of life, developmental delay, seizures, microcephaly, movement and balance disorders, hand-flapping, frequent outbursts of inappropriate laughter.
Collection Procedure
- Amniotic fluid 15-20 ml. Discard the first 2 ml of fluid to reduce the risk of maternal cell contamination. Aseptically transfer the specimen into sterile plastic conical tubes labeled with patient’s name and date of birth.
- CVS 10-1-20 mg. Aseptically transfer the specimen into sterile plastic conical tubes containing sterile transport medium. Label tube with patient’s name and date of birth.
A completed test requisition form must be included with every sample. A transport kit is available upon request.
Specimen Requirements
FISH analysis is performed following cytogenetic analysis
Transport Temperature
Room temperature (DO NOT refrigerate, freeze or centrifuge)
Methodology
Laboratory Testing for Prader-Willi Syndrome (PWS) / Angelman Syndrome is performed on metaphase chromosomes utilizing Fluorescence in situ hybridization targeting chromosome 15.
Causes for Rejection
Frozen specimen, inappropriate container
Turnaround Time
24-48 hrs after completion of cytogenetic analysis