Table of Contents

Angelman Syndrome

Angelman Syndrome

Main Features

Severe developmental delay or intellectual disability
Severe speech impairment
Gait ataxia and/or tremulousness of the limbs
Apparent happy demeanor that includes frequent laughing, smiling, and excitability

Eye Findings

Strabismus
Refractive error
Deep-set eyes

Other Findings

Seizures
EEG shows large amplitude slow-spike waves

Etiology

Deletion or defect in 15q11.2-q13 (80%)
- Genes in this area control imprinting of other genes and several genes are imprinted in this area.
- Imprinting leads to methylation or inactivation of certain genes so that material and paternal genes don't both function simultaneously.
UBE3A mutation (11%)
- Codes for ubiquitin ligase protein
- Ubiquitination is a process of labeling proteins that targets them for degredation

Reference