Molecular Analysis in Angelman Syndrome. Prader-Willi Syndrome and Potental Mouse Models

Deletions or uniparental disomy for human chromosome 15q11q13 result in Prader-Willi Syndrome (PWS) and Angelman Syndrome (AS), depending upon the respective parental origin. Clinical and cytogenetic aspects of the two disorders are covered elsewhere in this book. Molecular studies have indicated that the extent of deletions in PWS and AS do not differ (Knoll et al, 1990). That deletions in PWS occurred predominantly on the paternal chromosome 15 was first demonstrated using cytogenetic polymorphisms (Butler et al, 1986), and we now know that all cases are paternal in origin (Nicholls et al, 1989a; Nicholls et al, 1989b; Butler, 1990). In contrast, deletions in AS always occur on the maternal chromosome 15 (Knoll et al, 1989).