Molecular characterization of mitochondrial transferRNAGln and transferRNAMet A4401G mutations in a Chinese family with hypertension.

Mutations in mitochondrial (mt)transfer (t)RNA (mt­tRNA) have been reported to serve important roles in hypertension. To determine the underlying molecular mechanisms of mt­tRNA mutations in hypertension, the present study screened for mt­tRNA mutations in a Chinese family with a high incidence of essential hypertension. Sequence analysis of the mt­tRNA genes in this family revealed the presence of an A4401G mutation in the glycine­and methionine­tRNA genes, and a G5821A mutation in the cysteine­tRNA (tRNACys) gene. The G5821A mutation was located at a position conserved in various species, and disrupted G6­C67 base­pairing. It was hypothesized that the G5821A mutation may decrease the baseline expression levels of tRNACys, and consequently result in failure of tRNA metabolism. The A4401G mutation was reported to cause the mitochondrial dysfunction responsible for hypertension. Thus, the combination of G5821A and A4401G mutations may contribute to the high incidence of hypertension in this family. Mt­tRNA mutations may serve as potential biomarkers for hypertension.