Deletions and mutations in the 5- α -reductase type 2 ( SRD5A2 ) gene have been identified in 46,XY disorders of sexual differentiation (DSD). The clinical spectrum is heterogeneous, varying from a normal female external genital appearance to clitoromegaly and isolated micropenis or microphallus associated with hypospadias of various degrees. We describe a 46,XY DSD patient with a homozygous c.307C > T (p.R103X) mutation in the SRD5A2 gene. The case presented with a normal female external genital phenotype. © 2012 by Walter de Gruyter, Berlin, Boston.