Novel point mutations in complete androgen insensitivity syndrome with incomplete müllerian regression: Two Taiwanese patients

Complete androgen insensitivity syndrome (CAIS) is a relatively rare X-linked disorder caused by androgen receptor gene (AR) mutations that result in complete impairment of genital virilisation. In these individuals, no müllerian derivatives are usually found; however, several sporadic cases of CAIS with müllerian remnants have been reported. In this paper, we report two novel point mutations of the AR gene resulting in two cases of CAIS with incomplete müllerian regression. Molecular studies of cases 1 and 2 showed novel missense mutations of the AR gene, with a methionine to threonine substitution at codon 749 (base 2608 T → C) in exon 5 and a methionine to lysine substitution at codon 787 (base 2722 T → A) in exon 6. Both patients received bilateral gonadectomy and inguinal hernia repair. The excised gonads proved to be testes with incomplete regression of the müllerian structures. Conclusion: Müllerian structures can be present in androgen insensitivity syndrome and the presence of a uterus therefore does not exclude this disorder. Further study of these patients may promote a better understanding of the pathogenesis.