Mitochondrial genes, mutations respiratory chain

Defects of nuclear DNA also cause mitochondrial diseases. As mentioned above, the vast majority of mitochondrial proteins are encoded by nDNA, synthesized in the cytoplasm and imported into the mitochondria through a complex series of steps. Diseases can be due to mutations in genes encoding respiratory chain subunits, ancillary proteins controlling the proper assembly of the respiratory chain complexes, proteins controlling the importation machinery, or proteins controlling the lipid composition of the inner membrane. All these disorders will be transmitted by mendelian inheritance. From a biochemical point of view, all areas of mitochondrial metabolism can be affected (see below). 

Bourgeron, T., Rustin, Chretien, D. etal. Mutation of a nuclear succinate dehydrogenase gene results in mitochondrial respiratory chain deficiency Nat. Genet. 11 44—149, 1995. 

Mutations in the genes that encode components of the respiratory chain, whether in the mitochondrial genes or in the nuclear... 

Deletions and point mutations involving mitochondrial DNA are common in follicular neoplasms of oncocytic type, but the role of these mutations in the genesis of the tumors is unknown.Mutations of the GRIM-19 gene, which is involved in the mitochondrial respiratory chain and in apoptosis, have been found in 15% of oncocytic carcinomas but do not occur in other thyroid tumor types. 

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