An extremely rare missense mutation of the androgen receptor gene in a Vietnamese family with complete androgen insensitivity syndrome

We report a Vietnamese family with complete androgen insensitivity syndrome that included several phenotypic females who have a 46,XY karyotype with an extremely rare mutation of the androgen receptor gene. The proband was a 27-year-old phenotypic adult female referred to our department for karyotyping due to primary amenorrhea. Ultrasound examination revealed a small uterus. Chromosomal analysis showed a 46,XY karyotype. A polymerase chain reaction assay revealed the presence of the sex-determining region Y gene. Next-generation sequencing detected the NM_000044.6(AR):c.2170C>T(p.Pro274Ser) mutation, which was confirmed by Sanger sequencing. There is only one previous report of this mutation in a child with complete androgen insensitivity syndrome. In the family presented in this study, there were four more phenotypic adult females with primary amenorrhea and a phenotypic female infant with testes in the inguinal canals. The infant (first cousin once removed of the proband) presented with inguinal hernia/swelling in a phenotypic female and one of the four abovementioned adults had similar genetic analysis results. This is the second report of a missense mutation NM 000044.6(AR):c.2170C>T in the world and the first study to document a pedigree consisting of several individuals with CAIS as a result of this mutation. The presence of a tiny uterus in the proband, which is a rare occurrence in complete androgen insensitivity syndrome, is a unique clinical indicator of the disorder’s variable expressivity.