title: Altered Methylation of IGF2 Locus 20 Years after Preterm Birth at Very Low Birth Weight.
abstract: People born preterm at very low birth weight (VLBW, ≤1500g) have higher rates of risk factors for adult-onset diseases, including cardiovascular diseases and type 2 diabetes. These risks may be mediated through epigenetic modification of genes that are critical to normal growth and development.
  
  
  
  We measured the methylation level of an imprinted insulin-like-growth-factor 2 (IGF2) locus (IGF2/H19) in young adults born preterm at VLBW and in their peers born at term. We studied 158 VLBW and 161 control subjects aged 18 to 27 years from the Helsinki Study of Very Low Birth Weight Adults. Methylation fraction at two IGF2 differentially methylated regions (DMRs) - IGF2 antisense transcript (IGF2AS, also known as IGF2 DMR0) and last exon of IGF2 (IGF2_05, also known as IGF2 DMR2) - were measured with Sequenom Epityper. We used linear regression and adjustment for covariates to compare methylation fractions at these DMRs between VLBW and control subjects.
  
  
  
  At one IGF2AS CpG site, methylation was significantly lower in VLBW than in control subjects, mean difference -0.017 (95% CI; -0.028, -0.005), P = 0.004. Methylation at IGF2_05 was not different between the groups.
  
  
  
  Methylation of IGF2AS is altered 20 years after preterm birth at VLBW. Altered methylation may be a mechanism of later increased disease risk but more data are needed to indicate causality.
authors.affiliation: Department of Health Promotion and Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland ; Children's Hospital, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Karoliina
authors.initials: K
authors.lastname: Wehkalampi
authors.forename: Mari
authors.initials: M
authors.lastname: Muurinen
authors.forename: Sara Bruce
authors.initials: SB
authors.lastname: Wirta
authors.forename: Katariina
authors.initials: K
authors.lastname: Hannula-Jouppi
authors.forename: Petteri
authors.initials: P
authors.lastname: Hovi
authors.forename: Anna-Liisa
authors.initials: AL
authors.lastname: Järvenpää
authors.forename: Johan G
authors.initials: JG
authors.lastname: Eriksson
authors.forename: Sture
authors.initials: S
authors.lastname: Andersson
authors.forename: Juha
authors.initials: J
authors.lastname: Kere
authors.forename: Eero
authors.initials: E
authors.lastname: Kajantie
mesh_terms: D000293:Adolescent; D000328:Adult; D019175:DNA Methylation; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D008297:Male; D012307:Risk Factors; D055815:Young Adult
chemical_list: C035170:IGF2 protein, human; D007335:Insulin-Like Growth Factor II