Andrew has Angelman Syndrome: 2009

What is Angelman Syndrome

A rare genetic/neurodevelopmantal disorder named after Dr.Harry Angelman,an English Paediatrician who first described the syndrome in 1965.
More commonly the cause is a deletion in the maternal chromosome 15 (70% of cases) but Angelman Syndrome can be caused by Paternal UPD (Uniparental disomy) (2-3%), UBE3A mutation (discovered in 1997) (5%),imprinting defects (2-5%). There can also be no known cause for Angelman Syndrome (20%). In some cases Angelman Syndrome can be hereditary. Angelman Syndrome affects both boys and girls.
A person with Angelman Syndrome has a normal life expectancy.