Complex mosaicism in sex reversed SRY+ male twins

Sex reversal is characterized by discordance between genetic and phenotypic sex. Most XX males result from an unequal interchange between X and Y chromosomes during paternal meiosis, therefore transferring SRY to the X chromosome, which explains the male development in the presence of an otherwise normal female karyotype. We present here the case of sex reversed SRY+ male twins with several cell lines. They consulted for infertility. The presence of SRY on an X chromosome was demonstrated by FISH. Their respective karyotypes were: 46,X,der(X)t(X;Y)(p22.3;p11.2)249]/45,X 12]/45,der(X)t(X;Y)(p22.3;p11.2)11]/47,XX,der(X)t(X;Y) (p22.3;p11.2)1]/47,X,der(X)t(X;Y)(p22.3;p11.2)x21]/50, XX,der(X)t(X;Y)(p22.3;p11.2)x41]/46,XX1] for the first twin (SH-1) and 46,X,der(X)t(X;Y)(p22.3;p11.2)108]/45,X 3]/47,XX,der(X)t(X;Y)(p22.3;p11.2)2]/45,der(X)t(X;Y) (p22.3;p11.2)1]/47,X,der(X)t(X;Y)(p22.3;p11.2)x21] for the second twin (SH-2). There are three different types of XX males: 1) with normal genitalia, 2) with genital ambiguity, and 3) XX true hermaphrodites. The phenotype of the twins presented in this report is consistent with what is generally seen in XX SRY+ males: they have normal genitalia.