Among the remaining 70 cases there were patients with chromosome abnormalities which are not included in the DSD classification as well as rare NR5A1 variants of uncertain significance and hypergonadotropic hypogonadism and microorchidism in 46,XY subjects.
We have screened a cohort of 26 patients with 46,XX (ovo)testicular DSD and identified three unrelated individuals with this NR5A1 variant (p.Arg92Trp), as well as one patient with a novel NR5A1 variant (c.779C>T; p.Ala260Val).
To study the functional properties of six novel missense mutations of the NR5A1 gene encoding the steroidogenic factor 1 (SF-1) identified in six patients with 46,XY disorders of sex development (DSD) and to describe their relative phenotype-genotype relationship.
Our results suggest that the broad phenotype in these heterozygous NR5A1 46,XY DSD subjects may well be explained by an oligogenic mode of inheritance, in which multiple hits, individually non-deleterious, may contribute to a DSD phenotype unique to each heterozygous SF-1/NR5A1 individual.
Mutations in NR5A1 have been reported as a frequent cause of 46,XY disorders of sex development (DSD) associated to a broad phenotypic spectrum ranging from infertility, ambiguous genitalia, anorchia to gonadal dygenesis and female genitalia.
In 46,XY individuals, NR5A1-related phenotypes may range from disorders of sex development (DSD) to oligo/azoospermia, and in 46,XX individuals, from 46,XX ovotesticular and testicular DSD to primary ovarian insufficiency (POI).
A variant in steroidogenic factor-1 (SF-1, encoded by the gene NR5A1), p.Arg92Trp, has recently been reported in multiple families with 46,XX ovotesticular or testicular disorders of sex development (DSD).
The identification of heterozygous individuals with this novel mutation may bring additional knowledge on structural modifications that may influence NR5A1 DNA-binding ability, and may also contribute to genotype-phenotype correlations in DSD.
Mutations identified by NR5A1 sequencing have been associated with disorders of sex development (DSD), ranging from sex reversal to severe hypospadias in 46,XY patients and premature ovarian failure (POF) in 46,XX patients.
NR5A1 mutations have been detected in 46,XY individuals with disorders of sexual development (DSD) but apparently normal adrenal function and in 46,XX women with normal sexual development yet primary ovarian insufficiency (POI).