Epigenetic variation during the adult lifespan: cross-sectional and longitudinal data on monozygotic twin pairs. Aging Cell

The accumulation of epigenetic changes was proposed to contrib-ute to the age-related increase in the risk of most common dis-eases. In this study on 230 monozygotic twin pairs (MZ pairs), aged 18–89 years, we investigated the occurrence of epigenetic changes over the adult lifespan. Using mass spectrometry, we investigated variation in global (LINE1) DNA methylation and in DNA methylation at INS, KCNQ1OT1, IGF2, GNASAS, ABCA1, LEP, and CRH, candidate loci for common diseases. Except for KCNQ1OT1, interindividual variation in locus-specific DNA methyl-ation was larger in old individuals than in young individuals, rang-ing from 1.2-fold larger at ABCA1 (P = 0.010) to 1.6-fold larger at INS (P = 3.7 · 10)07). Similarly, there was more within-MZ-pair dis-cordance in old as compared with young MZ pairs, except for GNASAS, ranging from an 8 % increase in discordance each decade at CRH (P = 8.9 · 10)06) to a 16 % increase each decade at LE