A study of mitochondrial DNA mutations in peripheral lymphocytes in an aging cohort

Somatic mutation in the mitochondrial genome occurs much more rapidly than in the nuclear genome and is a feature, possibly contributory, of the aging of cells and tissues. identifying mitochondrial sequence changes in blood DNA of elderly subjects may provide a maker for the epigenetic changes of mitochondrial DNA known to occur in tissues with lower cellular turnover and would also have implications for immunosenescence. No large-scale epidemiological studies have been reported previously. in this study we have established long-PCR banks of the mitochondrial genome from peripheral lymphocytes for an elderly cohort of 716 individuals with a range of measured aging phenotypes, and we have established assays for three widely reported mutations: the 4977bp and 8048bp deletions and point mutation A3243G. No individuals were identified with detectable heteroplasmy for these changes. implications for tissue and population prevalence are discussed. The mitochondrial long-PCR DNA banks established will be useful for a wide range of studies of somatic mutation and of germline haplotypes in relation to aging.