Schaaf-Yang syndrome (SYS) (OMIM 615547) is an autosomal dominant multi-system genetic disease caused by Melanoma antigen L2 (MAGEL2) gene mutations imprinted by mothers and expressed by fathers on 15q11–15q13 chromosomes in the critical region of Prader-Willi. Here, MAGEL2 is linked to Schaaf-Yang syndrome.