Mutations of the SRY-Responsive Enhancer of <i>SOX9</i> Are Uncommon in XY Gonadal Dysgenesis

During mouse sex determination, SRY upregulates the core testis-specific enhancer of <i>Sox9</i>, TESCO. Mutations in human <i>SRY</i> are found in one third of cases with XY pure gonadal dysgenesis (XY GD; Swyer syndrome), while two thirds remain unexplained. Heterozygous <i>SOX9</i> mutations can cause XY GD in association with the skeletal malformation syndrome campomelic dysplasia. We hypothesized that human TESCO mutations could cause isolated XY GD. Sixty-six XY GD cases with an intact <i>SRY</i> were analyzed for TESCO point mutations or deletions. No mutations were identified. We conclude that TESCO mutations are not a common cause of XY GD.