Poster Session 4
Category: Genetics
Poster Session 4
Ji Hoi Kim, MD (she/her/hers)
M.D.
Department of Obstetrics and Gynecology, Seoul National University College of Medicine
Seoul, Seoul-t'ukpyolsi, Republic of Korea
Leejae Cho, MS
Department of Forensic Medicine, Seoul National University College of Medicine
Seoul, Seoul-t'ukpyolsi, Republic of Korea
Jong Kwan Jun, MD, PhD
Professor
Department of Obstetrics and Gynecology, Ewha Womans University
Seoul, Seoul-t'ukpyolsi, Republic of Korea
Jong-Lyul Park, PhD
Aging Convergence Research Center, KRIBB
Daejeon, Taejon-jikhalsi, Republic of Korea
Hwan Young Lee, PhD
Department of Forensic Medicine, Seoul National University College of Medicine
Seoul, Seoul-t'ukpyolsi, Republic of Korea
Seung Mi Lee, MD, PhD
Department of Obstetrics and Gynecology, Seoul National University College of Medicine
Seoul, Seoul-t'ukpyolsi, Republic of Korea
Epigenetic age acceleration (EAA) is the residual from regressing DNA methylation-based gestational age (GA) on actual GA, reflecting differences in biological aging rates. This study assessed developmental differences in preterm birth by measuring EAA using DNA methylation clocks. We compared epigenetic differences by chorionicity in monozygotic twins to examine the link between gestational age at delivery and EAA.
Study Design:
DNA methylation and clinical data were obtained from cord blood samples of 102 monozygotic twins at our center. Among them, 26 pairs and 2 individuals from dichorionic diamniotic (DCDA) pregnancies (19 full-term, 7 preterm and 2 individuals preterm) and 24 pairs from monochorionic diamniotic (MCDA) pregnancies (14 full-term, 10 preterm). Zygosity was determined with sex of neonates, chorionicity, and DNA analysis. Methylation profiling was done using the Illumina EPIC v2.0 microarray. Samples were classified as preterm (< 37 weeks) or full-term (³ 37 weeks). DNA methylation gestational age was estimated to be using Knight GA clock and Bohlin GA clock. EAA was calculated as the residuals from regressing of DNAm GA on actual GA. Differences in EAA between preterm and full-term were analyzed by t-tests.
Results:
Preterm infants showed high EAA than full-term in both chorionicity, with significance observed using Knight GA clock (p=0.033). In DCDA twins, full-term infants had low EAA while preterm showed high EAA(Knight GA clock, p=0.024), whereas MCDA twins exhibited high EAA regardless of gestational age (Knight GA clock, p=0.65). We examined clinical factors that might explain the EAA pattern in MCDA full-term infants but found no differences between DCDA and MCDA groups, except for maternal age, height, and body mass index.
Conclusion:
EAA patterns differed between preterm and full-term infants and were significantly influenced by chorionicity. MCDA twins exhibited high EAA regardless of gestational age, suggesting that sharing placenta may cause physiological stress even at full term. The highlight the role of chorionicity in interpreting gestational age and development.