Vivi was born in 2014 with Prader–Willi syndrome (PWS) , a genetic disorder caused by loss of function of specific genes. About 70% of cases occur when part of the father's chromosome 15 is deleted. In another 25% of cases the person has two copies of chromosome 15 from their mother and none from their father. As parts of the chromosome from the mother are turned off they end up with no working copies of certain genes. Prader–Willi syndrome has no cure. Treatment, however, may improve outcomes, especially if carried out early.
There are many signs and symptoms of Prader–Willi syndrome. The symptoms can range from poor muscle tone during infancy to behavioral problems in early childhood. Aspects seen in a clinical overview include hypotonia and abnormal neurologic function, hypogonadism, developmental and cognitive delays, hyperphagia and obesity, short stature, and behavioral and psychiatric disturbances.
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.
Learn more @PWSAUSA.ORG