Expanding the genes in the targeted next generation dystonia panels including SLC18A2 (VMAT2 deficiency), AADC gene (AADC deficiency), QDPR (DHPR deficiency) and PTS (PTPS deficiency) would preempt the necessity of CSF neurotransmitter metabolite measurements. The gene discussed is DDC; the disease is aromatic L-amino acid decarboxylase deficiency.