Polymorphisms, mutations, and epigenetic changes in the AR, CYR61, HSD17B3, HSD3B1, MAMLD1, SRD5A2, and STARD3 have been associated to hypospadias risk in severe types of hypospadias that have not been found in mild hypospadias (26–30). Here, HSD17B3 is linked to hypospadias.