Mutations in
mitochondrial DNA are associated with the pathogenesis of
essential hypertension. We report here the clinical, genetic, and molecular characterization of a three-generation Han Chinese family with
essential hypertension. Most strikingly, this family exhibited a high penetrance of
essential hypertension. Sequence analysis of the mitochondrial genome showed the presence of a homoplasmic T5655C mutation in
tRNAAla, together with the A4401G mutation in the adjacent region between
tRNAMet and
tRNAGln. Notably, the T5655C mutation was localized at the acceptor arm of
tRNAAla, disrupted the high conserved base-pairing (1A-72T), and may impair the
tRNA function. Moreover, the A4401G mutation was reported to decrease the steady-state level of
tRNAMet and
tRNAGln, and consequently caused the
mitochondrial dysfunction responsible for
hypertension. Taken together, the combination of T5655C and A4401G mutations in mitochondrial
tRNA genes may account for the high penetrance and expressivity of
hypertension in this Chinese family. Thus, our findings may provide new insight into the pathogenesis of this disorder.