Gonadal dysgenesis and its variants

Comprehending gonadal failure in phenotypic females with privation of sex chromosome material has improved over the past decade. Continued inquiry in X inactivation is somatic and germ cells and recent identification and quantitation of H-Y antigen have provided further insight into genetic factors affecting ovarian and testicular development. Gonadal dysgenesis in chromosomally intact 46,XX individuals is still a source of mystery and requires further investigation of the genetic control of ovarian development. The concept of gonadal receptor to H-Y antigen has provided for a better understanding of the H-Y antigen function in the 46,XY gonadal dysgenesis. Future availability of H-Y antigen determination will serve for easy detection of the Y component unrecognizable by current cytogenetic techniques in the 45,X gonadal dysgenesis subjects. In all etiologic groups, gonadal failure is the consistent lesion and recent longitudinal radioimmunoassay measurements of gonadotropin levels have shown the biphasic pattern of gonadotropin secretion before attaining the typical castrate level seen in agonadal children at the anticipated time of puberty. Biphasic pattern of gonadotropins is characterized by high levels of gonadotropins from birth to five years of age, followed by lower levels from ages five to nine and gradual increase to higher adult levels after age nine in normal females or to castrate agonadal levels in patients with gonadal dysgenesis. Long-term hormonal replacement therapy in this particular group of young females with gonadal dysgenesis deserves a critical prospective and retrospective assessment as to its role in the development of adenocarcinoma of the endometrium. An appropriate dose and schedule regimen for estrogen and progestin is of utmost importance in the prevention of this complication.