Basically, the occurrence of PWS is due to lack of several genes on one of an individual's two chromosome 15s―the one normally contributed by the father. In the majority of cases, there is a deletion―the critical genes are somehow lost from the chromosome. In most of the remaining cases, the entire chromosome from the father is missing and there are instead two chromosome 15s from the mother (uniparental disomy). The critical paternal genes lacking in people with PWS have a role in the regulation of appetite. This is an area of active research in a number of laboratories around the world, since understanding this defect may be very helpful not only to those with PWS but to understanding obesity in otherwise normal people.
People with PWS have a flaw in the hypothalamus part of their brain, which normally registers feelings of hunger and satiety. While the problem is not yet fully understood, it is apparent that people with this flaw never feel full; they have a continuous urge to eat that they cannot learn to control. To compound this problem, people with PWS need less food than their peers without the syndrome because their bodies have less muscle and tend to burn fewer calories.
Who to contact for more information:
Contact the Prader-Willi Syndrome Association (USA) (PWSA (USA)) at (800) 926-4797 toll-free in the US or (941) 312-0400 or visit their website at www.pwsausa.org PWSA (USA), a 501(c)(3) organization, is the only national membership organization that is dedicated to improving the lives of all persons afflicted with Prader-Willi syndrome and supporting them at every stage of life through research, education, support and advocacy. Headquartered in Sarasota, FL, it was formed in 1975 to provide a vehicle of communication for parents, professionals, and other interested citizens. Hospitals, physicians, and parents from all over the world consult with PWSA (USA) with medical emergencies and questions daily.
