Angelman Syndrome

Description of Angelman Syndrome:

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Complex genetic disorder affecting the nervous system. It is characterized by severe learning difficulties, motor dysfunction, seizure disorder, and often a happy, sociable disposition. Prevalence:

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Affects approximately 1 in 15,000 individuals (Margolis et al) Epidemiology/ Etiology:

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       -Onset is usually before the age of 3 (Margolis)
       -Caused by 4 molecular mechanisms (Kishino)

Maternal deletions of chromosome 15q11-q13 (70-80%) Intragenic mutation in maternally inherited UBE3A which is found in chromosome 15q11-q13 (10-20%) Paternal uniparental disomy (UPD) in chromosome 15q11-q13 (3-5%) Imprinting defects in chromosome 15q11-q13 which change the expression of UBE3A (3-5%) Those with deletion have more severe disease and those with UPD and imprinting have less severe defects (Margolis)