Boston Children's Hospital researchers found heart muscles accumulate new genetic mutations starting in childhood.
Many people thought heart cells were less susceptible to mutation because they don't continue to divide, but the new research suggests that mutations accumulate in heart cells as fast or faster than in other cell types, including some cells that divide.
Researchers studied cells from 12 children and adults from infancy to 82 years who had died from causes unrelated to heart disease. They sequenced the complete genomes of 56 individual heart muscle cells then compared the number of new, non-inherited mutations in cells of different ages.
The older the individual, the more single-nucleotide DNA variants in their heart cells. Researchers estimate that starting in infancy, each heart cell gains more than 100 new mutations each year. The pattern suggests that many of the mutations were caused by oxidative damage.
Researchers noted their study did not prove that mutations were involved in heart disease, though it may be a potential contributing factor over time.