A syndrome characterized by severe hypotonia,
poor feeding in early infancy followed
later in infancy by excessive eating that, can
lead to obesity if left unchecked. Children with PWS
show developmental delay, mild-to-moderate mental
retardation with multiple learning disabilities.
Hypogonadism is present in females. Short stature and
small hands and feet are also common.
Prader-Willi syndrome is due to a chromosome deletion
involving loss of material from chromosome region 15q11-q13.
The loss is consistently from the father's contribution
of chromosome region 15q11-q13. A child with P'wS can
have two copies of chromosome region 15q11-13 but both
from the mother. The opposite condition occurs in patients
with Angelman syndrome, with the deletion occurring on
the maternal region.
There is currently no specific treatment or cure for
PWS. Parents are advised to limit consumption of high-calorie
foods, and to use techniques such as special education,
speech therapy, and physical therapy to maximize the
Methylation studies can also be performed for this disorder.
Methodology: Fluorescent in Situ Hybridization (FISH) Analysis
Purpose: Confirmation of Clinical Diagnosis/Methylation Studies Negative
ICD-10 Code Q87.1
Test Requisition: Cytogenetics Requisition
Turn-around-time: 7-10 days