Prader-Willi Syndrome (PWS)

Prader-Willi syndrome is a complex non-hereditary birth defect resulting from an abnormality on the 15th chromosome. It occurs in males and females equally and in all races. PWS typically causes low muscle tone, short stature (if not treated with growth hormone), and incomplete sexual development. PWS also causes a chronic feeling of hunger that, along with a metabolism that utilizes drastically fewer calories than normal, can lead to excessive eating and life-threatening obesity if not controlled. The food compulsion makes constant supervision necessary. Average IQ is typically 70 which is slightly below “normal” average IQ, but even those with normal IQs are likely to have learning difficulties and require special education. Social and motor deficits also exist. At birth the infant typically has low birth weight for their gestational age, hypotonia (weak muscles), and difficulty sucking due to the hypotonia (which may cause “failure to thrive”). The second stage (“thriving too well”), with onset between the ages of two and five, is usually characterized by increased appetite, weight control issues, and motor development delays along with various behavior problems and medical issues resulting from obesity.

Useful Links:

Prader-Willi Syndrome Association
(http://www.pwsausa.org/)

MedlinePlus – Prader-Willi Syndrome
(http://www.nlm.nih.gov/medlineplus/praderwillisyndrome.html)

The Foundation for Prader-Willi Research
(http://www.fpwr.org/)

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