Prader-Willi Syndrome is a disorder which is sometimes associated with, but not a subtype of, autism. The classical features of this disorder include an obsession with food which is often associated with impulsive eating, compact body build, underdeveloped sexual characteristics, and poor muscle tone. Because of their obsession with food, many people afflicted with Prader-Willi Syndrome are overweight.
Most individuals afflicted with Prader-Willi Syndrome have mild mental retardation.
Some of the behaviors which are common to both Prader-Willi Syndrome and autism are: delays in language and motor development, learning disabilities, feeding problems in infancy, sleep disturbances, skin picking, temper tantrums, and a high pain threshold.
Prader-Willi Syndrome affects approximately 1 in 10,000 people. Most individuals suffering from this disorder are missing a small portion of chromosome 15 which appears to come from the paternal side of the family. When a small portion of chromosome 15 is missing and comes from the maternal side, the person may suffer from Angelman Syndrome.
The most effective form of treatment for people suffering from Prader-Willi Syndrome is behavior modification. In general, medications do not appear to very effective for these individuals.