Molecular investigation of mutations in androgen receptor and 5-alpha-reductase-2 genes in 46,XY Disorders of Sex Development with normal testicular development.

Abstract

In this study, we aimed to determine androgen receptor (AR) and SRD5A2 gene mutations in 45 patients characterised by 46,XY Disorders of Sex Differentiation (DSD) signs with normal testicular development referred to the Children's Medical Center from February 2015 to September 2017. Karyotype and sex hormone analyses were performed. Cytogenetic investigation showed that seven patients were 46,XX DSD, six patients were chromosomal DSD and 32 patients were 46,XY DSD. Eight exons of the AR gene and five exons of the SRD5A2 gene were amplified. Two cases were affected with androgen insensitivity syndrome (AIS) (missense mutation on exon 7, position c.3637 G>A: p.R841H and position c.3610 G>A: p.R832Q), one case was affected with 5-alpha-reductase deficiency type 2 (missense mutation at c.578A>G: p.N193S on exon 4), and 22 cases (88%) did not demonstrate AIS or 5α-RD2 gene abnormality. Due to the great impact of these disorders on human lifestyle, evaluation of genes involved can improve genetic counselling and therapeutic management. We focused on the AR and SRD5A2 genes in patients with 46,XY DSDs with normal testicular development referred to the Children's Medical Center from all over the country to eventually culminate in a reliable prenatal diagnosis protocol at this major referral centre giving service to a great number of families with consanguineous marriages.