Familial Xy Gonadal Dysgenesis

Abstract

XY pure gonadal dysgenesis has been found in three phenotypic females in three different sibships in the same family. The proposita, a maternal cousin and a maternal aunt are similarly affected. They are all of normal stature, possess uteri, but lack spontaneous secondary sexual development. There are no signs of Turner's syndrome. All are sex chromatin negative and have a normal 46 XY male karyotype. Streak gonads were surgically removed from the proposita, and one contained a microscopic focus of sex-cord tumor. Since the disorder is extremely rare and occurred in three sibships of a single family it is most probably gene determined. If so, the abnormal gene or genes are maternally transmitted and probably either X-linked or carried on an autosome and expressed only in chromosomal males. Whether the abnormal genes directly suppress testis-determining loci on the Y chromosome or block some early stage of testicular morphogenesis is not known.