Heteroplasmy of the human mtDNA control region remains constant during life

In a longitudinal, retrospective study, we monitored the level of heteropla smy at nucleotide position (nt) 309 and nt 16189 of the control region of h uman mtDNA. As a unique source of DNA, we analyzed multiple cervical-cell s amples collected, during 1 or 2 decades, from four women with heteroplasmy at either nt 309 or nt 16189. According to accurate, quantitative analysis by solid-phase minisequencing, the level of heteroplasmy remained stable in the cervical-cell samples from all four women during the time studied. We also analyzed autopsy samples from several different tissues, all containin g nt 309 in heteroplasmic form, of one of the women, who was deceased. On t he basis of our results, heteroplasmy in the control region of mtDNA seems to be inherited and is not the result of somatic age-related accumulation.