Complete gonadal dysgenesis in clinical practice: the 46,XY karyotype accounts for more than one third of cases

ObjectiveTo determine the frequency of XY karyotypes among females with complete gonadal dysgenesis (CGD) and to investigate the frequency of both gonadal tumors and SRY mutations.DesignRetrospective study based on data from all patients with CGD seen in our service from 1989 to 2010.SettingClinic for disorders of sex development, University Hospital, State University of Campinas.Patient(s)Thirty-two patients with hypergonadotropic hypogonadism, streak gonads, internal and external female genitalia, and normal karyotype (46,XX or 46,XY); 31 were index cases and 29 did not have a previously determined karyotype.Intervention(s)None.Main Outcome Measure(s)None.Result(s)The percentage of XY karyotypes among patients with CGD was 34.5% (10/29). Mean age at diagnosis among XY and XX patients was 17.4 years and 19.9 years, respectively. Gonadal tumors were found in 4 of 9 XY girls, and 7 of 10 had SRY gene mutations.Conclusion(s)The previously unreported finding of an elevated frequency of 46,XY karyotype among patients with CGD and the high risk of gonadal neoplasia in such cases indicate that this diagnosis must be kept in mind by clinicians and strengthen the importance of karyotype analysis in females with primary hypogonadism. In addition, the frequency of SRY mutations in XY CGD might be higher than previously considered.