Food choice in people with Prader-Willi syndrome: quantity and relative preference.

Two experiments were conducted to examine differences between people with Prader-Willi syndrome and an obese comparison group in choosing a larger quantity of food delivered after a delay (15, 30, or 60 seconds) or a small quantity of food delivered immediately. Individuals with Prader-Willi syndrome selected the larger food quantity. Choices by the obese comparison group tended to be equally divided between both options. Relative food preference influenced choosing the larger, delayed option in both groups. This effect appeared to be larger in the non-Prader-Willi syndrome group, but was not statistically significant. These results suggest perceived differences in food quantity may be an important determinant of food choice of people with Prader-Willi syndrome.

Prader-Willi Syndrome: Genetics and Behavior.

Since its inception, the John F. Kennedy Center has attempted to overcome developmental problems, which create restrictive barriers to the participation of individuals with specific disabilities in our broader society. Some of Nicholas Hobbs's earliest efforts involved developing strategies for preventing children's emotional and behavior problems, which interfered with their later full participation in society. Other investigators in the Kennedy Center explored ways of reducing dysfunctional repetitive movement problems and self-injury commonly associated with autism and severe mental retardation. We have become concerned about a group of people who have the potential to live largely independently (or semi-independently), to work at meaningful jobs in the community, and to make full use of the same recreational and leisure opportunities as other members of society but who are prevented from doing so because of a life-threatening behavior problem. Prader-Willi syndrome (PWS) is a genetic developmental disability characterized by a group of specific behavioral features of which an insatiable appetite is the most striking. PWS is the most commonly known genetic cause of obesity. The eating disorder associated with PWS can be so severe as to be life threatening, including eating to the point of stomach rupture and death. Though a cluster of commonly covarying clinical features are exhibited by people with this syndrome, only the eating disorder is common to all affected individuals. PWS shares behavioral features with other disorders and disabilities, such as obsessive compulsive disorder and autism, but only PWS includes the unique combination of characteristics that distinguish this syndrome. Because eating disorders such as bulimia and anorexia nervosa also share features with PWS, any light that could be shed on the causes and treatment of the eating disorder in PWS could potentially have far-reaching implications for other eating disorders as well. In this article, we review the behavioral, cognitive, and other psychological features of PWS and explore their relationships to known genetic mechanisms.