Fig. 3. Diagnostic flow for DRD and DRD-plus phenotypes.
The disorders in the gray boxes are relatively common etiologies in each category. The DAT abnormality in the cases of SOX6 mutation has not been proven yet, but is very likely. Based on the experimental research, SOX6 gene is linked to development and survival of dopaminergic neurons in the substantia nigra.
DRD = dopa-responsive dystonia, [D] = DRD, [D+] = DRD-plus.