Angelman syndrome

Information about:

Angelman syndrome 

(Angelman syndrome, OMIM 105830)

by Karen Grønskov, Zeynep Tümer

Clinical characteristics

A clinical diagnosis of Angelman syndrome (AS) demands fulfillment of four major criteria and minimum three of the six minor criteria. The major criteria are severe developmental delay, movement or balance disorder, severe limitations in speech and language and typical abnormal behavior including happy demeanor and excessive laughter. The six minor criteria are postnatal microcephaly, seizures, abnormal EEG, sleep disturbance, attraction to or fascination with water, and drooling (Tan et al. 2011). The unique clinical features do not usually manifest within the first year of life, but developmental delay is noticed around 6 months of age. The diagnosis of AS is a combination of clinical and molecular genetic diagnosis. In about 10% of the individuals with a clinical diagnosis of AS it is not possible to find the underlying genetic mechanism and other diagnoses should be considered.

Genetic background:

Molecular mechanisms:


Tables & figures: