GNAS and 2q37 microdeletion syndrome: Therefore, in the present study, we screened 65 patients affected with broad sporadic GNAS imprinting defects, with (n = 32) or without signs of AHO (n = 33), for the presence of BDMR-associated 2q37 deletions in order to find genes possibly involved in the phenotypic heterogeneity observed in iPPSD3.