Novel mitochondrial tRNA 3261A > g mutation in two pedigrees with essential hypertension.

BACKGROUND

Essential hypertension (EH) was associated with mitochondrial tRNA mutations.

AIMS

This study was designed to assess the association between EH and mitochondrial dysfunction.

METHODS

A total of 30 individuals from two different Chinese families exhibit maternally inherited EH were assessed for genetic, clinical, and biochemical phenotypes pertaining to EH and mitochondrial functionality. These analyses included assessments of tRNA 3261A > G mutation status, mitochondrial membrane permeability, mitochondria-associated ATP and reactive oxygen species (ROS) generation, and electron transport chain functionality.

RESULTS

EH was detected in 6 total analyzed members of the two families assessed in the present study, with its initial age of onset and presentation varying among patients. These patients with EH exhibited the tRNA 3261A > G mutation and were of the B5 and D4 Eastern Asian mitochondrial haplogroups. This 3261A > G mutation was predicted to result in disruption of normal tRNA activity owing to the destabilization of conserved base pairing (30A-40U). Consistent with this prediction, we found that cybrid cell lines exhibiting this 3261A > G mutation exhibited a ~49.05% decrease in baseline tRNA levels. These cells additionally exhibited ~44.81% reductions in rates of mitochondrial translation.

CONCLUSIONS

To facilitate future molecular diagnosis, the 3261A > G mutation should be included in the list of hereditary risk factors. Our findings will aid in the counseling of EH families.