GWAS for developmental defects of the male reproductive system have also identified candidate genes for hormonal (AR, steroidogenesis, ESR1, and ESR2) and nonhormonal (FGF8, FGFR2, BMP4, and BMP7) pathways underlying hypospadias (Carmichael et al. 2013; Geller et al. 2014). This evidence concerns the gene BMP7 and hypospadias.