Normal growth in Angelman syndrome due to paternal UPD.

We describe 2 patients with Angelman syndrome (AS) due to paternal uniparental disomy (UPD). One patient is a female aged 30 years and the other a male aged 4 1/2 years. Both have the characteristic wide mouth and big chin, moderate mental retardation, virtually no speech but some 30 words of sign language and a happy disposition with outbursts of laughter. Ataxia is minimal in both patients, manifesting mainly when they are excited or running. Both patients are tall (height around 90th percentile), have a head circumference around 75th percentile and are overweight (weight over the 97th percentile). These cases add to the knowledge of the possibility of normal or increased growth parameters, particularly weight, in AS when the genetic mechanism is paternal UPD.