Analysis of heteroplasmy in the major noncoding region of mitochondrial DNA in the blood and atherosclerotic plaques of carotid arteries

For identification of somatic mitochondrial DNA (mtDNA) mutations, the mtDNA major noncoding region (D-loop) sequence in blood samples and carotid atherosclerosis plaques from patients with atherosclerosis was analyzed. Five point heteroplasmic positions were observed in 4 of 23 individuals (17%). Only in two cases could heteroplasmy have resulted from somatic mutation, whereas three heteroplasmic positions were found in both vascular tissue and blood. In addition, length heteroplasmy in a polycytosine stretches was registered at nucleotide positions 303-315 in 16 individuals, and also in the 16184-16193 region in four patients. The results suggest that somatic mtDNA mutations can occur during atherosclerosis, but some heteroplasmic mutations may appear in all tissues, possibly being inherited.