Presence of mutation m.14484T>C in a Chinese family with maternally inherited essential hypertension but no expression of LHON

Abstract

Essential hypertension (EH, MIM 145500) is the most common cardiovascular disease and affects one-quarter of the world's adult population. Families with EH in a mode of maternal transmission have been occasionally observed in clinical settings and suggested an involvement of mitochondrial DNA (mtDNA) mutation. We aimed to characterize the role of mtDNA mutation in EH. We reported a large Han Chinese family with a maternally inherited EH and an extraordinarily high percentage of sudden death mainly in affected females. Analysis of the entire mtDNA genome of the proband identified a homoplasmic primary mutation m.14484T>C for Leber's hereditary optic neuropathy (LHON), along with several variants indicating haplogroup F1 status. Intriguingly, no maternal member in this family had LHON though they all harbored m.14484T>C. The arterial stiffness of the members carrying mutation m.14484T>C was significantly increased than that of non-maternal members without this mutation. No environmental factor (including age, sex, smoking, diabetes, hyperlipidemia) was correlated with the decreased aortic elastic properties observed in affected members. Mitochondrial respiration rate and membrane potential (ΔΨm) were significantly reduced in lymphoblastoid cell lines established from affected members carrying m.14484T>C when compared to control cell lines (P<0.05). There was an elevation of reactive oxygen species and a compensatory increase of mitochondrial mass in mutant cell lines. Our results suggest that m.14484T>C causes EH under certain circumstance. This study provides a paradigm for diverse phenotypes of the primary LHON mutation and suggests for the necessity of routine cardiac evaluation in patients with the primary LHON mutation.