They are also sometimes given a secondary diagnosis of autism. In 1965,
Harry Angelman, M.D., an English physician, was the first to describe a group of individuals with similar behavioral and physical similarities, which was later termed 'Angelman Syndrome.'
For many of these individuals, a small portion of chromosome 15 is missing; and this appears to be from the maternal side. Interestingly, when a small portion of chromosome 15 is missing and is from the paternal side, the child may suffer from Prader-Willi Syndrome.
Similar to autism, individuals with Angelman Syndrome display the following behaviors: hand-flapping, little or no speech, attention deficits, hyperactivity, feeding and sleeping problems, and delays in motor development. These individuals may also engage in biting and hair pulling.
In contrast to autism, people with Angelman Syndrome are often described as very sociable. They are very affectionate and engage in frequent laughing. The majority of these individuals have abnormal EEG's and epilepsy. Many tend to have a stiff-legged gait and jerky body movements. These individuals also have common facial features, such as a wide smiling mouth, a thin upper lip, and deep set eyes. More than half have low levels of pigmentation in their eyes, hair, and skin.
The prevalence rate of Angelman Syndrome is estimated to be 1 in 25,000 individuals, and the majority of these individuals are described as severely mentally retarded.
Suggested interventions for Angelman Syndrome include: