Analysis of the gene coding for steroidogenic factor 1 (SF1, NR5A1) in a cohort of 50 Egyptian patients with 46,XY disorders of sex development

Abstract

Objective: Steroidogenic factor 1 (SF1, NR5A1) is a key transcriptional regulator of genes involved in the hypothalamicpituitary-gonadal axis. Recently, SF1 mutations were found to be a frequent cause of 46,XY disorders of sex development (DSD) in humans. We investigate the frequency of NR5A1 mutations in an Egyptian cohort of XY DSD. Design: Clinical assessment, endocrine evaluation and genetic analysis of 50 Egyptian XY DSD patients (without adrenal insufficiency) with a wide phenotypic spectrum. Methods: Molecular analysis of NR5A1 gene by direct sequencing followed by in vitro functional analysis of the two novel missense mutations detected. Results: Three novel heterozygous mutations of the coding region in patients with hypospadias were detected. p.Glu121AlafsX25 results in severely truncated protein, p.Arg62Cys lies in DNA-binding zinc finger, whereas p.Ala154Thr lies in the hinge region of SF1 protein. Transactivation assays using reporter constructs carrying promoters of anti-Mü llerian hormone (AMH), CYP11A1 and TESCO core enhancer of Sox9 showed that p.Ala154Thr and p.Arg62Cys mutations result in aberrant biological activity of NR5A1. A total of 17 patients (34%) harboured the p.Gly146Ala polymorphism. Conclusion: We identified two novel NR5A1 mutations showing impaired function in 23 Egyptian XY DSD patients with hypospadias (8.5%). This is the first study searching for NR5A1 mutations in oriental patients from the Middle East and Arab region with XY DSD and no adrenal insufficiency, revealing a frequency similar to that in European patients (6.5-15%). We recommend screening of NR5A1 in patients with hypospadias and gonadal dysgenesis. Yearly follow-ups of gonadal function and early cryoconservation of sperms should be performed in XY DSD patients with NR5A1 mutations given the risk of future fertility problems due to early gonadal failure.

Wide spectrum of NR5A1‐related phenotypes in 46,XY and 46,XX individuals

“…Progressive androgen production and virilization in adolescence has been observed in several XY patients with NR5A1 mutations, in contrast to the severe undervirilized external genitalia found in most patients (Cools et al, 2012; Gabriel Ribeiro de Andrade et al, 2014; Tantawy et al, 2014; Fabbri et al, 2016). The almost normal testosterone levels after hCG stimulation or at pubertal age suggest that NR5A1 action may be less implicated in pubertal steroidogenesis than during fetal life.…”

“…More than 80 different NR5A1 variants, distributed across the full length of the protein, have been described and the majority are nonsynonymous mutations (Pedace et al, 2014; Tantawy et al, 2014; Woo et al, 2015; Fabbri et al, 2016). Most of these mutations are located in the DBD and are in a heterozygous state or compound heterozygous state with the p.Gly146Ala (rs1110061) variant, with the exception of two mild mutations described in homozygous state (Achermann et al, 2002; Soardi et al, 2010).…”

“…The reviewed data of seventy‐two 46,XY DSD patients with NR5A1 mutations reported in the literature, for whom information on presence or absence of Müllerian derivatives was available, suggested that Müllerian derivatives are present in about 24% of the cases (Pedace et al, 2014; Tantawy et al, 2014; Woo et al, 2015; Fabbri et al, 2016). However, persistently elevated FSH levels after puberty found in all patients studied suggest an impairment of Sertoli cells function in post pubertal age (Pedace et al, 2014).…”

The spectrum of 46XY disorders of sex development in a University centre in Saudi Arabia

“…Genetic variations within the pathway interrupt normal male development and will lead to malformation of the external and or internal genitalia (1)(2)(3)(4)(5)(6). Steroidogenic factor 1 (SF1, NR5A1) is currently a key transcriptional regulator of genes involved in the hypothalamic-pituitary-gonadal axis and SF1 mutations were found to be a frequent cause of 46XY disorders of sex development (DSD) (7). Yet, the investigation for SF1 mutation was not performed in our patients in this study.…”

Molecular regulation of steroidogenesis in endocrine Leydig cells

“…Upon transplantation into Leydig cell-depleted rats, these in vitro-generated Leydig cells could further developed into functional ALC and restore serum testosterone levels [94]. Mutations in the human SF1 gene are also a frequent cause of 46, XY disorders of sex development often associated with improper Leydig cell differentiation and function [95][96][97][98][99][100][101][102].…”