Androgen Insensitivity Syndrome: A Rare Cause of Primary Amenorrhoea

Abstract

Androgen Insensitivity Syndrome (AIS) is a rare X-linked Disorder of Sexual Differentiation (DSD) caused by a mutation in the Androgen Receptor (AR) gene, which is located on the X chromosome (Xq11-q12). It can present with a wide spectrum of phenotypes depending on different mutations of the AR gene. It is classified into mild, partial, and complete AIS. In this series of cases, authors describe patients who presented to tertiary hospitals over several years. Case 1 presented with inguinal masses and primary amenorrhoea, which upon investigations revealed complete AIS. Case 2 was a young child who underwent surgery for an inguinal hernia, and later histopathology and karyotype revealed a diagnosis of complete AIS. Case 3 presented with large adnexal masses to oncology, where intraoperatively absent Mullerian structures, histopathology, and karyotype gave the diagnosis of Complete AIS. Case 4 presented with hirsutism, primary amenorrhoea, and clitoromegaly. Upon investigation, imaging and karyotype with virilising features led to the diagnosis of partial AIS. The absence of Mullerian structures on imaging, chromosomal analysis, and the finding of undescended testicular masses in inguinal regions clinch the diagnosis. These patients should undergo gonadectomy after puberty to decrease the chances of malignancy. Therefore, when investigating the cases of primary amenorrhoea, patients with absent pubic/axillary hair and absent uterus/ovaries should raise suspicion of AIS. Also, any young female child with an inguinal hernia should be investigated for AIS.

Keywords

• androgen receptor gene
• case series
• disorder of sexual differentiation
• karyotype
• phenotypical sex
• x- linked disorder