Prader-Willi syndrome

Both Angelman (AS) and Prader-Willi (PWS) syndromes may be caused by deletions on the long arm of chromosome 15. Maternal deletions lead to AS while paternal deletions result in PWS. Seventy percent of both AS and PWS are caused by deletions on the long arm of chromosome 15. These disorders affect the nervous system and, while both result in developmental delay, each presents with its own unique clinical features. View testing options