A 46,XY female with mixed gonadal dysgenesis and a 48,XY,+7,+i(12p) chromosome pattern in a primary gonadal tumor

Cytogenetic analysis of a primary germ-cell tumor originating from the streak gonad of a 20-year-old phenotypic female with a 46,XY karyotype and mixed gonadal dysgenesis revealed a 48,XY,+7,+i(12p) chromosomal pattern. Germ-cell tumors originating from gonads of normal males are usually highly aneuploid. An isochromosome 12p as well as an overrepresentation of chromosome 7 material are among the specific changes most consistently observed. The present case shows that tumors of dysgenetic gonads, albeit being near-diploid, may exhibit similar chromosomal changes. This observation lends additional support to the hypothesis that these specific cytogenetic anomalies may play an important role in the pathogenesis of human germ-cell tumors.