The mitochondrial tRNAMet/tRNAGlnA4401G and tRNACysG5821A mutations may be associated with hypertension in two Han Chinese families

Mitochondrial tRNA genes are the hot spots for mutations associated with essential hypertension. We report here the clinical and molecular genetic characterization of two Han Chinese pedigrees with materially inherited essential hypertension. Clinical evaluation revealed the variable severity and age-at-onset of hypertension among matrilineal relatives. In particular, the age-at-onset of hypertension in the maternal kindred ranged from 36 years to 79 years. The sequence analysis of entire mitochondrial genome in two probands showed that two probands carried the identical homoplasmic tRNAMet/tRNAGlnA4401G and tRNACysG5821A mutations and distinct sets of polymorphisms belonging to East Asian haplogroup C. The A4401G mutation may affect the processing of the precursors of tRNAMet and tRNAGln , thereby altering the tRNA metabolism. The tRNACys G5821A mutation is located in the acceptor stem of tRNACys. This mutation may abol-ish the predicted G6-C67 pairing and consequently affect the structure and stability of mitochondrial tRNACys, thereby leading to mitochondrial dysfunction. Therefore, these data suggested that the tRNAMet/tRNAGlnA4401G and tRNACys G5821A mutations are likely associated with essential hypertension in these two Chinese pedigrees.