The role of mitochondrial genome in essential hypertension in a Chinese Han population

Abstract

Earlier genetic studies of essential hypertension have focused on nuclear genes or family-based mitochondrial screening in Caucasian and African-American pedigrees. The role of mitochondria in sporadic Chinese hypertensives is unknown. We sequenced mitochondrial genomes in 306 age- and gender-balanced Chinese Han hypertensives and controls. In 153 hypertensives, putative functional changes included 4 changes in rRNA genes, 11 changes in tRNA genes and 25 amino-acid substitutions. The remaining variants were synonymous changes or non-coding regions. In the 153 controls, 2 base changes in the tRNA genes and 13 amino-acid substitutions were found. A8701G in ATP6 gene (belongs to haplogroup M; P=0.0001) and C8414T in ATP8 gene (belongs to haplogroup D; P=0.01) were detected significantly different in the cases and controls. Interestingly, the cases were more likely to have two or more amino-acid changes and RNA variants compared with the controls (57.43 versus 23.81%, P=0.0001). In addition, several variants we found were highly conserved and/or specifically located at the 3' end adjacent to the anticodon, which may contribute to the stabilization of structure, and thus lead to the decrease of tRNA metabolism. In conclusion, mitochondrial SNPs (mtSNPs) may affect the course of hypertension in sporadic Chinese hypertensives. Some specific mtSNP within mitochondria may have potential role in the Chinese hypertensives due to their function. Synergetic interaction between mitochondrial mtSNPs and/or haplogroups is needed to be investigated in the future.