TFAP2C and fragile X syndrome: Xue et al. found several genes (WNT1, BMP4, POU3F4, TFAP2C, PAX3, KCNA1, KCNC3, KCNG4, KCNJ3, KCNK9 and KCNT1) associated with neuronal differentiation of fragile X syndrome, which is a common hereditary disorder associated with intellectual limitations18.