A common mutation of the MYH gene is associated with increased DNA oxidation and age-related diseases

Abstract

We describe a common mutation of the MYH gene, which is involved in the repair of oxidative damage to DNA, and its relationship to age, levels of 8-OHdG, and circulating levels of interleukin-1. We studied 1146 "healthy" and 562 unselected Chinese subjects. We observed a reverse insertion of the AluYb8 sequence (AluYb8MYH) to be homozygous in approximately 25.8% of the healthy Chinese population age 20-29 years, with the incidence of homozygosity decreasing to 15.7% by age 50-59 years. Because subjects were selected on the basis of absence of disease during medical screening, this suggests that homozygosity for this gene has a marked impact on the development of age-related or chronic diseases or mortality. Because the MYH gene is involved in DNA repair we assessed whether homozygous carriage of this gene was associated with increased levels of 8-OHdG in the leukocytic DNA of carriers. The level of 8-OHdG increased from 3.8 8-OHdG/10(6) dG in wild-type carriers to 10.8 8-OHdG/10(6) dG in homozygous carriers, suggesting that the presence of the mutation was associated with impaired DNA repair. Because this mutation might be associated with the increased development of age-related or chronic disease and inflammation, we also measured plasma concentrations of interleukin-1, which increases with aging and chronic disease. We observed a highly significant increase in plasma interleukin-1 in patients homozygous for the AluYb8 insertion in the MYH gene consistent with accelerated aging or development of undiagnosed disease in homozygous subjects. Screening for this genetic variation may have predictive value in assessing potential longevity of subjects in China, as well as in the Western world.