XY gonadal dysgenesis in three siblings.

Three tall, phenotypic female siblings with XY gonadal dysgenesis were found to have short fourth metacarpal bones (bilateral in two and unilateral in the other). Clitoromegaly was observed in the two older siblings, without hirsutism. Bilateral streak gonads were found in all three. A gonadoblastoma was present in the left streak gonad of the youngest, and an adenomatoid tumor in the left streak gonad of the oldest, who was diabetic. Determination of androgens from peripheral and gonadal venous plasma revealed androgen secretion by the streak gonads. On the basis of clinical findings, familial tendency, and androgen secretion from the streak gonads in these patients, it is proposed that the XY gonadal dysgenesis represents a severe form of male pseudohermaphroditism.