Chances for AS:

 

Again, it is very hard to say how common AS is because there are so many misdiagnosis'. The closest estimate would be 1 in 15,000 but because of the vastness of misdiagnosis' it could be anywhere from 1 in 10,000 to 1 in 20,000.

 

Angelman syndrome usually isn't detected until parents begin to notice developmental delays when a baby is about 6 to 12 months old. Seizures often begin when a child is between 2 and 3 years old