Answer:
Angelman Syndrome affects one in 12,000 to one in 20,000 individuals. Exact numbers of people who have the syndrome are unknown, but can be estimated by: 1,854,057,000 (estimated world population of people less than 15 years old from the PRB 2008 Data Sheet) divided by 12,000 and by 20,000: somewhere between 92,702 and 154,504 individuals.