Phenotypic Variation and Pubertal Outcomes in Males and Females with 46,XY Partial Gonadal Dysgenesis

Background 46,XY gonadal dysgenesis is classified as complete (CGD) or partial (PGD) subtypes. The phenotype of PGD and the long-term outcome is not clearly defined. Objective To evaluate clinical features and pubertal outcome of PGD in a large cohort, using CGD as a comparator for diagnostic clarity. Methods Patients with 46,XY GD were identified from the I-DSD Registry and data on phenotype, genetics, biochemistry, gonadal histology, and pubertal development were collated in 3 categories; CGD (n = 100), PGD assigned female (PGDf, n = 107), and male (PGDm, n = 103) at birth. Results Most individuals with PGD presented with atypical genitalia in infancy, though, 18% of PGDf presented with delayed puberty and 8% with virilization. A genetic etiology was identified in 42% of the cohort, with common gene defects in SRY and WT1 in CGD and NR5A1 in PGD. Gonadal pre-/malignancy was found in 33.8% in CGD, 19.7% in PGDf, and 8.8% in PGDm. Among the PGDm (>13 years) with at least 1 gonad, 80% had spontaneous pubertal onset and 59% achieved Tanner G5 without hormone treatment. Labioscrotal gonads at presentation and testosterone response to human chorionic gonadotropin predicted onset of spontaneous puberty. In PGDf with gonads, 42% developed spontaneous virilization at puberty. Sex was reassigned in 16.1% and 5.3% of individuals with PGDf and PGDm, respectively. Conclusion This study highlights the heterogeneous phenotype of PGD and the consequent diagnostic challenge. Many PGD patients with preserved gonads have the potential to develop puberty spontaneously, though further study is needed to determine the risk of developing gonadal tumors.