MIXED GONADAL-DYSGENESIS - CLINICAL, CYTOGENETIC, ENDOCRINOLOGIC, ANDHISTOPATHOLOGICAL FINDINGS IN 16 PATIENTS

We describe clinical, cytogenetic, endocrine, and histopathological fi ndings in 16 patients with mixed gonadal dysgenesis (MGD). All patient s except 1 presented genital ambiguity and 10 of them had Ullrich-Turn er manifestations. The 45,X/46,XY karyotype was the most frequent with a predominance of 45,X cells in both peripheral lymphocytes and gonad s. In all cases Mullerian and Wolffian remnants and/or derivatives wer e found and in some patients both Wolffian- and Mullerian-derived stru ctures were identified on the streak or testicular side. Postpubertal patients exhibited variable degrees of virilization and all of them ha d hypergonadotropism coexisting with low to normal baseline serum leve ls of testosterone; their testicular response to human chorionic gonad otropin (HCG) in terms of testosterone secretion was also variable, ra nging from minimal to almost a normal response. All prepubertal patien ts but 1 had normal baseline levels of pituitary gonadotropins and tes tosterone and their gonadal response to the HCG challenge was highly v ariable. With the exception of 1 case, who had a 45X/46XY(p-) karyotyp e, no correlation between the cytogenetic data and degree of external genital ambiguity and the hormonal findings was observed. Additional i nformation on the specific structural abnormalities involving the test is-determining gene of the Y chromosome in patients with MGD is needed in order to further understand the mechanisms responsible for the wid e variability characteristic of this disorder.