We detected a 14% reduction in the density of inhibitory synapses in MS compared to control (MS: 0.299 ± 0.006 GAD+ synapses/μm2 neuronal membrane vs. control: 0.348 ± 0.009 GAD+ synapses/μm2 neuronal membrane, p = 0.005) (Figure 3A) with no differences detected between HLA‐DRB1*15 genotype groups (15+: 0.3 ± 0.008 GAD+ synapses/μm2 neuronal membrane vs. 15−: 0.297 ± 0.008 GAD+ synapses/μm2 neuronal membrane, p = 0.493) (Figure 3A). This evidence concerns the gene HLA-DRB1 and myeloid sarcoma.