Heterologous Inferential Analysis (HIA) and Other Emerging Concepts: In Understanding Mitochondrial Variation In Pathogenesis: There is no More Low-Hanging Fruit

Here we summarize our latest efforts to elucidate the role of mtDNA variantsMtDNA variants affecting the mitochondrial translation machinery, namely variants mapping to the mt-rRNA and mt-tRNA genes. Evidence is accumulating to suggest that the cellular response to interference with mitochondrial translation is different from that occurring as a result of mutations in genes encoding OXPHOS Oxidative phosphorylation (OXPHOS) proteins. As a result, it appears safe to state that a complete view of mitochondrial diseaseMitochondrial diseases will not be obtained until we understand the effect of mt-rRNA and mt-tRNA variants on mitochondrial protein synthesis. Despite the identification of a large number of potentially pathogenic variants in the mitochondrially encoded rRNA (mt-rRNA) genes, we lack direct methods to firmly establish their pathogenicity. In the absence of such methods, we have devised an indirect approach named heterologous inferential analysis (HIA Heterologous inferentialaAnalysis (HIA) ) that can be used to make predictions concerning the disruptive potential of a large subset of mt-rRNA variants. We have used HIA Heterologous inferentialaAnalysis (HIA) to explore the mutational landscape of 12S and 16S mt-rRNA genes. Our HIA Heterologous inferentialaAnalysis (HIA) studies include a thorough classification of all rare variants reported in the literature as well as others obtained from studies performed in collaboration with physicians. HIA Heterologous inferentialaAnalysis (HIA) has also been used with non-mammalian mt-rRNA genes to elucidate how mitotypes influence the interaction of the individual and the environment. Regarding mt-tRNA variations, rapidly growing evidence shows that the spectrum of mutationsMutations causing mitochondrial diseaseMitochondrial diseases might differ between the different mitochondrial haplogroups seen in human populations.