Heart Disease Risk Linked to Mitochondrial Mutation

Researchers have identified a mutation in the mitochondrial genome that is expressed in people with high blood pressure and elevated cholesterol levels, which are risk factors for cardiovascular disease.

Investigators at Yale University (New Haven, CT, USA) and Syracuse University (NY, USA) worked with a large family (142 individuals spanning four generations) that had many members suffering from a syndrome that included hypertension, hypercholesterolemia, and hypomagnesemia. The syndrome was transmitted by the female relatives with a pattern indicative of mitochondrial inheritance.

Studying the mitochondrial DNA from the female members of the family, the investigators reported in October 21, 2004, online edition of Science Express that they had identified a homoplasmic mutation substituting cytidine for uridine adjacent to the mitochondrial tRNA-Ile anticodon. Uridine is almost always found at this position in tRNAs, as it aids in stabilizing the anticodon loop. Since mitochondrial function is known to decrease with aging in parallel with increasing likelihood of developing cardiovascular diseases, the authors speculate that mutations in mitochondrial DNA may be involved.

"Looking further, this finding raises the possibility that all features of the metabolic syndrome may be attributable to altered mitochondrial function,” said senior author Dr. Richard T. Lifton, professor of genetics at Yale University.