Clinical, Hormonal, Genetic, and Molecular Characteristics in Androgen Insensitivity Syndrome in an Asian Indian Cohort from a Single Centre in Western India

Abstract

The study aimed to analyze clinical and hormonal phenotype,and genotype in patients with genetically proven androgen insensitivity syndrome (AIS) from Western India. Index patients with pathogenic variants in the androgen receptor (AR) gene were identified from a consecutive 46,XY DSD cohort (n = 150) evaluated with clinical exome sequencing, and their genetically-proven affected relatives were also included. In sum, 15 index cases (9 complete AIS [CAIS] and 6 partial AIS [PAIS]) were identified making AIS the second most common (10%) cause of 46,XY DSD, next to 5α-reductase 2 deficiency (n = 26; 17.3%). Most patients presented late in the postpubertal period with primary amenorrhoea in CAIS (89%) and atypical genitalia with gynecomastia in PAIS (71.4%). All CAIS were reared as females and 83.3% of PAIS as males with no gender dysphoria. Four of 6 patients with available testosterone to dihydrotestosterone ratio had a false elevation (>10). Metastatic dysgerminoma was seen in 1 patient in CAIS, while none in the PAIS group had malignancy. Fifteen different (including 6 novel) pathogenic/likely pathogenic variants in AR were found. Nonsense and frameshift variants exclusively led to CAIS phenotype, whereas missense variants led to variable phenotypes. In this largest, monocentric study from the Asian Indian subcontinent, AIS was the second most common cause of 46,XY DSD with similar phenotype but later presentation when compared to cases in the rest of the world. The study reports 6 novel pathogenic variants in AR.