Background: Steroid-5α-reductase-2 (SRD5A2) and 17β-hydroxysteroid dehydrogenase type 3 (17β-HSD3) enzyme deficiencies are frequent causes of 46, XY disorder of sex development (46, XY DSD), where an infant with 46, XY has a female phenotype. We assessed the hydroxy-steroid-17β-dehydrogenase-3 (HSD17B3)and SRD5A2 genes in twenty Iranian phenotypic females with 46,XY DSD. Materials and methods: All exons in HSD17B3 and SRD5A2 genes were subjected to PCR amplification followed by sequencing. Results: Of 20 identified 46, XY DSD patients, one had a homozygous missense 17β-HSD3 mutation Ser65Leu (c.194C > T). We found 1 SRD5A2 novel homozygous missense mutation of Tyr242Asp (c.891T > G) in exon 5, which in-silico analyses revealed that this mutation may have deleterious impact on ligand binding site of SRD5A2 protein. Three other individuals harbored 17β-HSD3 deficiencies without identified mutations. Conclusions: SRD5A2 and 17β-HSD3 mutations are found in 10% of 46, XY DSD Iranian patients.
Keywords: 46 XY disorders; Steroid 5-a reductase; mutation; sex development.