SRY ALONE CAN INDUCE NORMAL-MALE SEXUAL-DIFFERENTIATION

Most individuals with the rare 46,XX male ''syndrome'' arise due to an unequal interchange between Xp and Yp termini during paternal meiosis . The pattern of Y-sequences in these patients varies considerably, bu t very few cases have been reported showing only SRY. The phenotype in these patients is also variable ranging from severe impairment of the external genitalia through hypospadias and/or cryptorchidism to occas ional normal male phenotype. We report a Mexican 46,XX male patient wi thout genital ambiguities in whom DNA analysis showed the presence of SRY and the absence of ZFY. We conclude that in this case SRY alone wa s enough for complete male sexual differentiation. (C) 1995 Wiley-Liss , Inc.