Four Novel NR5A1 Mutations in 46,XY Gonadal Dysgenesis Patients Including Frameshift Mutations with Altered Subcellular SF-1 Localization

Abstract

46,XY gonadal dysgenesis (46,XY GD) is a disorder of sexual development caused by mutations in genes involved in early gonadal development (bipotential gonads) and testis differentiation. In 46,XY GD individuals, mutations of the SRY gene are detected most frequently, followed by mutations in the NR5A1 (SF-1) gene, but in a lot of cases, the underlying molecular mechanism remains elusive. In this study, we retrospectively performed sequence analyses of the NR5A1 (SF-1) gene in 84 patients with complete, partial, and syndromic forms of 46,XY GD. In total, 7 heterozygous mutations were found in 6 of 84 patients (7.1%). Among these, we identified 4 mutations that, to the best of our knowledge, have not been reported before (c.268G>T, c.369del, c.871-1G>C, and c.893T>C). Transfection of different mutations revealed altered subcellular localization of the mutant SF-1 protein in the case of the frameshift mutations, indicating an impaired protein function. In conclusion, we present 4 novel mutations of the NR5A1 gene associated with 46,XY GD together with in vitro data pointing towards a possible functional impairment of the mutant SF-1 proteins.

Keywords: 46,XY gonadal dysgenesis; NR5A1; SF-1.