Abstract

Gender dysphoria is commonly thought to arise from discrepant cerebral and genital sexual differentiation. Increasing evidence supports the idea of genetic vulnerability. The purpose of this paper was to investigate whether the polymorphism CYP17-MspA1 rs743572 is associated with gender dysphoria. Fragments that included the rs743572 polymorphism were PCR amplified and digested with MspA1 in 317 MtFs, 223 FtMs, 358 control men and 264 control women. The allele/genotype frequencies were compared between groups, with the 1000 Genomes Data Base and with international literature. Allele and genotype frequencies did not differ significantly between the FtM and female control groups (chi(2) = 0.631; p = 0.43 and chi(2) = 2.767; p = 0.25), or between the MtF and male control groups (chi(2) = 0.105; p = 0.74 and chi(2) = 0.789; p = 0.67). A2 frequency was higher in the FtM (0.43) than the female control group (0.41), male control group (0.40), or MtF group (0.39), but this difference did not reach statistical significance. Genotype frequencies did not differ significantly between groups (p = 0.66), between genotypes (p = 0.4) or between sexes (p = 0.66). Our data contradict previous findings about the CYP17-MspA1 rs743572 polymorphism and gender dysphoria and concur with the 1000 Genomes Data Base, which shows that the allele frequencies vary between countries and ethnicities but not between sexes. Our data do not support a hypothetical involvement of the rs743572 polymorphism in the genetic basis of gender dysphoria.