PRADER-WILLI SYNDROME (PWS) and ANGELMAN SYNDROME (AS) are distinct neurogenetic disorders, both usually caused by chromosomal deletions on chromosome 15q11 or by uniparental disomy. The chromosomal alterations result in an aberrant expression profile of gene loci that are subject to imprinting. Absence of a paternal allele of chromosome 15q11, due to chromosomal deletion or uniparental disomy,...
