Prader-Willi syndrome is a genetic condition that causes excessive hunger, decreased mental capacity, short stature, and weak muscle tone ("floppiness"). Children with Prader-Willi syndrome have an intense craving for food and usually become obese.

There is no specific treatment or cure for Prader-Willi syndrome. But those caring for a child with Prader-Willi syndrome can strictly limit food intake to prevent obesity, which can cause serious health problems. Treatment with growth hormone may increase growth and improve physical strength.