In all cortical regions, there was a significant main effect of the mean optical intensity of parvalbumin+ calcium‐binding protein (CBP) across all groups (Kruskal–Wallis, P < 0.05) with post hoc analyses revealing a significant loss of parvalbumin+ intensity within the majority of Alpers' syndrome patient parvalbumin+ interneurons relative to controls (P < 0.05) (supporting information Figure S6). This evidence concerns the gene PVALB and Alpers syndrome.