SRY-positive 46,XX male with cryptorchidism as the only presenting clinical feature

The SRY gene, located on the short arm of the Y chromosome, is responsible for differentiation of the testis from the undifferentiated gonad. We report a 4-year-old patient with male phenotype and female karyotype (46,XX) with cryptorchidism as the only presenting clinical abnormality. Fluorescent in situ hybridization analysis, using Y- and X-specific (whole chromosome painting WCP Y WCP X) DNA and SRY probes, detected a small Y chromosome fragment, including the SRY gene, transferred to the short arm of the X chromosome.