title: Individual variation and longitudinal pattern of genome-wide DNA methylation from birth to the first two years of life.
abstract: Prenatal development and early childhood are critical periods for establishing the tissue-specific epigenome, and may have a profound impact on health and disease in later life. However, epigenomic profiles at birth and in early childhood remain largely unexplored. The focus of this report is to examine the individual variation and longitudinal pattern of genome-wide DNA methylation levels from birth through the first two years of life in 105 Black children (59 males and 46 females) enrolled at the Boston Medical Center. We performed epigenomic mapping of cord blood at birth and venous blood samples from the same set of children within the first two years of life using Illumina Infinium Humanmethylation27 BeadChip. We observed a wide range of inter-individual variations in genome-wide methylation at each time point including lower levels at CpG islands, TSS200, 5'UTR and 1st Exon locations, but significantly higher levels in CpG shores, shelves, TSS1500, gene body and 3'UTR. We identified CpG sites with significant intra-individual longitudinal changes in the first two years of life throughout the genome. Specifically, we identified 159 CpG sites in males and 149 CpG sites in females with significant longitudinal changes defined by both statistical significance and magnitude of changes. These significant CpG sites appeared to be located within genes with important biological functions including immunity and inflammation. Further studies are needed to replicate our findings, including analysis by specific cell types, and link those individual variations and longitudinal changes with specific health outcomes in early childhood and later life.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA. wangdeli@gmail.com
authors.forename: Deli
authors.initials: D
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhou
authors.forename: Hehuang
authors.initials: H
authors.lastname: Xie
authors.forename: Xiumei
authors.initials: X
authors.lastname: Hong
authors.forename: Hui-Ju
authors.initials: HJ
authors.lastname: Tsai
authors.forename: Guoying
authors.initials: G
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Liu
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Wang
mesh_terms: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D001499:Bayes Theorem; D002675:Child, Preschool; D018899:CpG Islands; D019175:DNA Methylation; D005260:Female; D014644:Genetic Variation; D016678:Genome; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D024363:Transcription Initiation Site
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions