Mixed gonadal dysgenesis and sex chromosome mosaicism with multiple cell lines including structural aberrations of the Y chromosome.

A case of mixed (asymmetric) gonadal dysgenesis is reported in a girl with ambiguous external genitalia, a right intra-abdominal testis, a left streak gonad containing follicle-like structures devoid of oocytes and bilateral Mullerian derivatives. Buccal smear cells were X-chromatin negative and a Y-chromatin body was present in 31% of cells. Cytogenetic studies in peripheral blood leucocyte cultures showed sex chromosome mosaicism with cell lines including structural abnormalities of the Y chromosome in 36% of the cells: 45,X/46,XY/46,X + i(Yp)/46,X, + Yq-/47,XYY/47,XY + Yq-.