POLG and inborn mitochondrial metabolism disorder: While this closely concerns mitochondrial diseases, the impact of dysfunctional mitochondria on other organelles is likely to be relevant for the understanding of neurodegenerative syndromes that involve chronically defective mitochondria (e.g., Parkinson’s disease triggered by mutations in mitochondrial genes such as POLG and PARK2, as well as rotenone-induced Parkisonism).