POLG and inborn mitochondrial metabolism disorder: Meanwhile, our analysis did not reveal significant differences in mitochondrial mass (measured using anti-Porin1/VADC1) by between PD and mitochondrial disease cases (mtDNA point mutations or POLG) or controls (Fig. 3l), nor in the abundance of test MQC proteins between neurons carrying a mtDNA point mutation and PD (Fig. 3b–k).