GPC1 and hereditary disease: Moreover, in Simpson–Golabi–Behmel syndrome, a human genetic disease characterized by overgrowth (Pilia et al. 1996), where aberrant function of GPC3 affects Hh signaling (Capurro et al. 2008), none of the other glypican family members can substitute for GPC3 (Yoneda et al. 2012).