Angelman syndrome

Patients appear normal at birth. Eating disorders and hypotension can occur in the first 6 months of life, followed by a delay in psycho-motor development from 6 months to 2 years. Typically, the characteristic symptoms of AS appear from the first year of life with severe mental retardation, lack of speech, fits of laughter associated with stereotypical hand movements, microcephaly, macrostomy, hypoplasia of the upper jaw, prognathism and neurological disorders, with a "puppet-like" gait, ataxia and seizures associated with specific abnormalities of the electroencephalogram (EEG; three-phase delta activity with peaks in the frontal regions). Other clinical signs include a happy appearance, hyperactivity without aggression, low alertness, anxiety, sleep disturbances associated with decreased need for sleep, high sensitivity to heat, and craving for water.