More importantly, we also found that the distribution frequencies of CC/CT/TT genotypes and two alleles (C and T) at RYR1 C6487T polymorphism showed statistical significance between two groups, suggesting that RYR1 C6487T polymorphism may contribute to the susceptibility to hypospadias. RYR1 gene was extensively expressed in the skeletal muscle that was involved in the release of Ca2+channel from the SR and excitation-contraction coupling of the skeletal muscle, thus resulting in muscle contraction [19]. This evidence concerns the gene RYR1 and hypospadias.