Since it is the week of Siena’s PWS Walk, I have decided to post PWS info every day this week… and HERE we go! To learn more about PWS – visit http://www.pwsausa.org/ – to learn more about Siena’s PWS Walk 2011 – http://sienaswalk.orgfree.com/
Q: What is known about the genetic abnormality?
A: 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.
Q: What causes the appetite and obesity problems in PWS?
A: 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.