Indeed, CSF‐HVA levels and HVA:5‐HIAA ratios were comparable to those observed in TH deficiency, an inherited dopamine synthesis defect associated with central dopamine deficiency.20 In order to determine how DNAJC6 mutations may impact the dopaminergic system, we used patient CSF to analyze proteins involved in dopamine signaling and homeostasis. Here, DNAJC6 is linked to tyrosine hydroxylase deficiency.