For many chromosomal disorders, we wonder which of the genes within the critical region account for the main clinical features of the overall condition. In Prader-Willi syndrome (PWS), which is caused by the absence of paternally expressed genes on chromosome 15, the role of the MAGEL2 gene has been highlighted by the identification of individuals with point mutations in just that gene. Those share several clinical features with individuals affected with PWS. The condition caused by those point mutations has been named Schaaf-Yang syndrome (SYS). This study is the first to explore hormonal and skeletal features of individuals with SYS. The findings suggest marked overlap between SYS and PWS, further underlining the important contributions of the MAGEL2 gene to PWS in general. (By Dr. Christian P. Schaaf, http://jmg.bmj.com/content/early/2018/03/01/jmedgenet-2017-105024 )

Schaaf Lab: First author John McCarthy (back row, second from left) and last author Christian Schaaf (back row, third from left)