Complete androgen insensitivity syndrome and discordant Müllerian remnants: two cases with novel mutation in the androgen receptor.

Complete androgen insensitivity syndrome (CAIS) associated with Müllerian remnant is rare during childhood. The Müllerian system usually regresses because of the presence of the anti-Müllerian hormone (AMH) originating from the Sertoli cells of the gonads. Rarely, residual Müllerian structures may exist. We present two cases from the same family, raised as females. They were 12 and 18 years old, respectively, and they had Tanner V breast development but Tanner I-II pubic hair. The older patient had primary amenorrhea. Both have a 46,XY genotype. Pelvic ultrasonography revealed no uterus and ovaries. The patients underwent bilateral laporoscopic gonadectomy. Both had residual Müllerian structures. Mutation analyses were performed, and both patients were found to be carrying a point mutation in exon 4 of the AR gene consisting of a G nucleotide deletion at position c.1890delG, followed by a frame-shift mutation and a stop codon. This mutation has not been described yet in the literature. Although the association with CAIS and Müllerian remnant is rare, no genetic defect specific to androgen insensitivity with Müllerian remnants has been identified so far.