Alternative titles and symbols : Happy puppet syndrome;
Included titles and symbols : Angelman syndrome chromosome region; ANCR;
Description : Angelman syndrome is a neurodevelopmental disorder characterized by mental retardation,
movement or balance disorder, typical abnormal behaviors, and severe limitations in
speech and language. Most cases are caused by absence of a maternal contribution to
the imprinted region on chromosome 15q11-q13. Prader-Willi syndrome (PWS; 176270)
is a clinically distinct disorder resulting from paternal deletion of the same 15q11-q13
region. In addition, the chromosome 15q11-q13 duplication syndrome (608636) shows
overlapping clinical features. Clayton-Smith and Pembrey (1992) provided a review
of Angelman syndrome. Cassidy and Schwartz (1998) reviewed the molecular and clinical
aspects of both Prader-Willi syndrome and Angelman syndrome. Horsthemke and Wagstaff
(2008) provided a detailed review of the mechanisms of imprinting of the Prader-Willi/Angelman
syndrome region. Van Buggenhout and Fryns (2009) provided a review of Angelman syndrome
and discussed genetic counseling of the disorder, which can show a recurrence risk
of up to 50%, depending on the underlying genetic mechanism.;
Inheritance : Autosomal dominant (loss of maternal allele);
Molecular basis : Caused by mutation in the ubiquitin protein ligase E3A gene (UBE3A, 601623.0001);