SLC18A2 and Parkinsonism: Moreover, genetic mutation of Pro316A in VMAT2 is linked to an infantile-onset form of parkinsonism.19 Compared with the TBZ-induced VMAT2T occluded structure, this set of luminal-gating residues in VMAT2YCR overlaps with the ones forming the VMAT2T luminal plug, including Pro45, Val131, and Pro313.