Impact of prematurity on LINE-1 promoter methylation

<b>Aim:</b> Promoter methylation of LINE-1 may be affected by prematurity, but there is little evidence in the literature.<b>Materials & methods:</b> Blood from premature and full-term neonates on days 0, 5, 30 and 90 was analyzed for DNA methylation percentage in a promoter region of the LINE-1, after bisulfite conversion and pyrosequencing.<b>Results:</b> Premature infants, as a whole, showed significantly lower methylation percentage at birth, but this difference diminished over time. However, the subgroup of extremely premature (<28 weeks gestational age) had higher methylation percentages, similar to full-term newborns.<b>Conclusion:</b> This research underscores the critical role of prematurity on the methylation pattern of LINE-1. These findings underline the complexity of epigenetic regulation in prematurity and emphasize the need for further studies.