SLC1A2 and Parkinson disease: However, we did find a decrease in transcripts in PD for the three known glutamate synthase genes (funMT, GLT1:K00264, GLU:K00284, and gltB:K00265, Fig. 3C, Mann–Whitney test, q = 0.004, q = 0.004, and p = 0.006, respectively) alongside a decrease in cheB in PD (K03412, protein-glutamate methylesterase/glutaminase, Fig. 3C, q < 0.01, Mann–Whitney test).