Complications associated with Angelman syndrome include:

 

Feeding difficulties: Some infants with Angelman syndrome have problems feeding during the first few months of life because of an inability to coordinate sucking and swallowing. If your child has difficulty feeding, your pediatrician may recommend a high-calorie formula to help your baby gain weight.

Hyperactivity: Many young children with Angelman syndrome have increased motor activity. They may move quickly from one activity to another, often keeping their hands or a toy in their mouths. Their attention span may be very short. Hyperactivity often decreases with age in children with Angelman syndrome, and medication usually isn't necessary.

Sleep disorders:It's common for people with Angelman syndrome to have abnormal sleep-wake patterns and to need less sleep than normal. In some cases, sleep difficulties may improve with age. Medication and behavior therapy may help control sleep disorders.

Curving of the spine (scoliosis): Some people with Angelman syndrome develop this abnormal side-to-side spinal curvature over time.

Obesity: 

Older children with Angelman syndrome tend to have large appetites, which lead to obesity.