Prader–Willi syndrome and Angelman syndrome


  • Karin Buiting

    Corresponding author
    • Institut für Humangenetik, Universitätsklinikum Essen, Hufelandstrasse 55, D-45122 Essen, Germany.
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    • Karin Buiting, Senior Scientist at the Institute of Human Genetics at the University Hospital Essen. Her main research interest is the role of genomic imprinting and the epigenetic mechanisms involved in human disease, especially in Prader–Willi and Angelman syndromes.

  • How to cite this article: Buiting K. 2010. Prader–Willi syndrome and Angelman syndrome. Am J Med Genet Part C Semin Med Genet 153C:365–376.


Prader–Willi syndrome (PWS) and Angelman syndrome (AS) are two distinct neurogenetic disorders in which imprinted genes on the proximal long arm of chromosome 15 are affected. Although the SNORD116 gene cluster has become a prime candidate for PWS, it cannot be excluded that other paternally expressed genes in the chromosomal region 15q11q13 contribute to the full phenotype. AS is caused by a deficiency of the UBE3A gene, which in the brain is expressed from the maternal allele only. The most frequent genetic lesions in both disorders are a de novo deletion of the chromosomal region 15q11q13, uniparental disomy 15, an imprinting defect or, in the case of AS, a mutation of the UBE3A gene. Microdeletions in a small number of patients with PWS and AS have led to the identification of the chromosome 15 imprinting center (IC). The IC consists of two critical elements, which act in cis to regulate imprinting in the whole chromosome 15q11q13 imprinted domain. © 2010 Wiley-Liss, Inc.