Obesity and Prader-Willi Syndrome

Article excerpt

Q Our 10-year-old son has been diagnosed with Prader-Willi syndrome (PWS). He has never had the chromosome testing for PWS, but he has many of its features.

He is gaining weight very rapidly and it is very difficult to control his appetite. If we try to stop him from eating he gets very angry, usually resulting in a major temper tantrum. He can't seem to understand why we do not give him all he wants to eat. We have had to put locks on the refrigerator and cupboards.

How can we help with his weight? I have heard that growth hormones can curb appetite and promote weight loss. What do you think?

Also, should we have a chromosome test run? If negative, does he have something other than PWS?

A The word syndrome refers to a group of physical features and symptoms believed to stem from the same cause. PWS is a chromosomal abnormality characterized by low muscle tone (hypotonia), short stature, developmental delays and excessive appetite (hyperphagia), that often results in obesity. Other features may include incomplete sexual development and behavioral problems, including stubbornness, temper tantrums and a tendency to "pick" at the skin. PWS occurs in approximately one in 10,000 newborns. There is no known cause.

It probably is not necessary to get the chromosome testing if your son has most of the PWS features. Test results are not 100-percent conclusive. In a substantial number of instances, it is possible to have PWS with a negative chromosome test.

Three factors cause the obesity associated with PWS. First, a malfunction in the hypothalamus means that people with PWS always feel hungry. And, their "thermostat" is set lower than normal, so they need fewer calories to maintain their weight than other people. Finally, they are typically less active than other people, so they burn fewer calories. These factors work together to result in obesity which is a potential health problem for children and becomes the most serious health problem facing adolescents and adults with PWS.

The first approach should be to restrict the calories your child gets, while maintaining a balanced diet with all essential nutrients. Ask your son's pediatrician to refer you to a registered dietician who has experience with children with special needs. You are already restricting access to food by using locks. This must be continued, not only at home but at other care-takers'. School lunchrooms, classroom parties and social events where there will be food are very difficult situations. …