GFAP and Alpers syndrome: Quantification of the mean optical intensity of the mitochondrial markers within GFAP + astrocytes revealed the Alpers’ syndrome patient group demonstrated significantly low (z-score < -2) to severely deficient (z-score < -4) levels of NDUFB8, and to a lesser extent COXI, compared to control astrocytes (P < 0.001) (Fig. 3b).