Sleep Abnormalities in Rare Genetic Disorders: AS, RTT, and PW

This study will investigate sleep behavior in subjects with Angelman Syndrome, Rett Syndrome or Prader-Willi Syndrome. The study will also investigate sleep behavior in healthy siblings of subjects with Angelman Syndrome, Rett Syndrome or Prader-Willi Syndrome. These individuals will serve as control subjects. The study will use questionnaires designed to identify sleep disorders and how they affect behavior and quality of life. The principal goals of this study are: 1. To see how common sleep disorders are in individuals with Angelman Syndrome, Rett Syndrome or Prader-Willi Syndrome; 2. To see how sleep disorders affect behavior in these individuals; 3. To see whether sleep disorders and related behavior problems improve or worsen with age; 4. To see how specific disease conditions relate to sleep disorders and how bad the sleep disorders are; 5. To develop new treatment options to improve quality of life and behavior issues; and 6. To evaluate current treatment options to improve sleep problems in these individuals.