Eating Problems in Prader-Willi Syndrome
Babies with Prader-Willi syndrome often are small at birth and do not have good control of their limbs as they begin to grow. They actually eat very little at first. But between ages one and four, they will generally begin to have a constant fascination with food -- and will pursue it at almost any cost. Where a normal person feels full, the person with Prader-Willi does not.
But it is not a matter of binge eating. A genetic irregularity causes a problem in the hypothalamus, the part of the brain that regulates several bodily functions including appetite. Because of this irregularity, the signals that would normally tell a person that he is full simply do not exist with Prader-Willi.
Unfortunately, those with Prader-Willi also need fewer calories than others to maintain a normal body weight. They're caught between this need for fewer calories on one hand and a desire for more calories all the time. The result is often very fast weight gain early in life.
Food for those with Prader-Willi must be restricted, preferably on a plan developed by a physician or a registered dietitian. If it isn't, the drive for more and more food is life-threatening. A person with Prader-Willi may actually gorge himself to death if allowed to have enough food. Another possibility is severe obesity that leads to other serious health risks that shorten life.
Other Components of Prader-Willi Syndrome
While constant hunger is a major part of Prader-Willi, it is far from the only symptom. Other major symptoms are serious as well:
- Cognitive impairment: The average IQ of those with Prader-Willi is 70, although some approach 100 and some are well under 70.
- Lack of muscle tone: While they put on weight as babies, the weak muscle tone at birth persists into later years. It appears that the general lack of muscle activity may be one reason that those with the disorder burn fewer calories.
- Abnormal physical development: People with Prader-Willi are often shorter than average, and many have almond-shaped eyes.
- Short tempers: Frustration can lead to tantrums, and frustration is common when it is necessary to deny food.
- Skin problems: Skin may be easily irritated, and many times the person worsens the problem by picking the skin to the point of damaging it.
Origins and Prevalence
While Prader-Willi syndrome is the result of a genetic defect, it is not one that appears to be passed down from parent to child. Researchers do not yet know how the abnormality happens; it seems to be an "accident" of nature.
The Prader-Willi Syndrome Association estimates a prevalence rate of 1 in 12,000 to 15,000 people. Solid numbers seem to be sketchy, however, since accurate diagnosis may not always occur.
Outlook and Treatment for Prader-Willi
Unfortunately, those with Prader-Willi need constant care for their entire lives. Without consistent monitoring, they are capable of finding ways around obstacles to food and harming themselves through massive caloric intake. A subdued environment characterized by calm and predictability helps to manage daily life.
Some popular support exists for testing Rimonabant, an appetite suppressant, as a treatment for overeating in Prader-Willi. Rimonabant is not approved by the FDA in the United States at this time, and how it might affect eating patterns in Prader-Willi remains to be seen.
There is limited research on giving growth hormone to those with Prader-Willi syndrome to address the partial growth hormone deficiency that generally accompanies it. In small studies, growth hormone seems to improve cognitive and motor functioning. However, this treatment method is not intended to address eating behaviors.
Sources:
Anorexia Nervosa and Related Eating Disorders, Inc. "Prader-Willi Syndrome." Formerly at http://www.anred.com/pw.html (link now defunct). Accessed 11 September 2007.
Höybye, C., Thorén, M., and Böhm, B. Cognitive, emotional, physical and social effects of growth hormone treatment in adults with Prader–Willi syndrome. Journal of Intellectual Disability Research 49 (2005): 245-252.
Prader-Willi Syndrome Association (UK). What Is Prader-Willi syndrome? Accessed 11 September 2007.
Prader-Willi Syndrome Association (USA). What Is Prader-Willi Syndrome? Accessed 11 September 2007.
