ESR1 and androgen insensitivity syndrome: Wu et al. [49], investigated the association of the polymorphism of estrogen receptor gene and they concluded that the AIS is associated to XbaI gene, however Takahashi et al. [50] in 2011 reported no relationship between the two regions at the chromosome X, related to the estrogen receptor genes, with the manifestation and severity of AIS, after performing an extensive study in the Japanese population.