SOX9 and disorder of sexual differentiation: We did not observe CN variation of the SOX9 gene, however we found two highly polymorphic CNVRs located upstream (CNVR1) and downstream (CNVR2) of SOX9. Although higher copy number in CNVR1 may be associated with XX DSD phenotype, it was detected in both cases and controls, and therefore cannot be considered as a causative mutation.