Methylation-specific polymerase chain reaction (MS-PCR) analysis of SNRPN gene was then performed using primers as previously described36,37, and the results confirmed that this patient had maternal uniparental isodisomy of the 15q11.2 region resulting in Prader-Willi syndrome (Supplementary Figure 3). Here, SNRPN is linked to Prader-Willi syndrome.