Prader Willi Syndrome (PWS)
Download a Test Requisition Form
You can download the Test Requisition form (106k) in portable document format (.pdf).
You must have Adobe Acrobat" Reader installed on your computer to read this file. You can download Adobe Acrobat" Reader at Adobe's Web site by selecting the version appropriate for your type of computer.
About the Disorder | Indications | Specimen l Testing Methodology l Sensitivity l Turnaround Time l Cost l CPT Codes l Shipping l Results l Contact Us
About the Disorder
Prader Willi Syndrome (PWS) is a rare genetic disorder that affects an individual's growth and development. The prevalence of PWS is approximately 1 in 15,000 births and affects children of both sexes and of all races. Infants with PWS are often first recognized by their low muscle tone, feeding difficulties, and failure to thrive. Older children and adults with PWS typically have unusual eating habits including hyperphagia that can result in morbid obesity. In addition, they often have hypogonadism, short stature, small hands / feet, mild to moderate mental retardation, as well as difficult behaviors including obsessive-compulsive disorder. PWS results from an absence of genetic material on one of an individual's #15 chromosomes that should have been contributed by the individual's father at the time of conception. About 70% of cases of PWS are due to a deletion of a portion of the paternal #15 chromosome. Nearly 30% of cases of PWS are due to the inheritance of two maternal #15 chromosomes (with no paternal contribution). In about 1-2% of cases, defects in the imprinting center of the paternal chromosome #15 account for PWS.
Back to Top
Indication
Confirmation of diagnosis in an individual with clinical features of PWS.
Back to Top
Specimen
At least 2ml of whole blood in purple top (EDTA) tube. Label tube with patient's name, birth date, and date of collection. Phlebotomist must initial tube to verify patient's identity.
Back to Top
Testing Methodology
Methylation specific polymerase chain reaction (PCR) is performed on sodium bisulfite treated DNA that allows specific amplification of the maternal (methylated) and paternal (un-methylated) SNRPN gene at 15q11-13.
Back to Top
Sensitivity
A maternal-only pattern is diagnostic of PWS. Additional studies including fluorescent in situ hybridization (FISH) to identify large gene deletions and uniparental disomy (UPD) analysis should be considered to determine the specific genetic etiology of the disorder for genetic counseling purposes.
Back to Top
Turnaround Time
2-3 weeks
Back to Top
Cost
Please call 866-450-4198 for current pricing.
Back to Top
CPT Codes
88391, 83894, 83901(x2), 83912
Back to Top
Shipping Instructions
Please enclose test requisition with sample. All information must be completed before sample can be processed. Place samples in Styrofoam mailer and ship at room temperature by overnight Federal Express to arrive Monday through Friday.
Ship to
Cytogenetics and Molecular Genetics Laboratories
3333 Burnet Avenue NRB 1042
Cincinnati, OH 45229
513-636-4474
Back to Top
Results
Results will be reported to the referring physician or designee as specified on the requisition form.
Back to Top
Contact Us
For additional inquiries, contact us:
Phone 513-636-4474
Fax 513-636-4373
Email moleculargenetics@cchmc.org
Back to Top
