Association of dna methylation with age, gender, and smoking in an arab population

Shaza Zaghlool, Mashael Al-Shafai, Wadha A. Al Muftah, Pankaj Kumar, Mario Falchi, Karsten Suhre

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

Background: Modification of DNA by methylation of cytosines at CpG dinucleotides is a widespread phenomenon that leads to changes in gene expression, thereby influencing and regulating many biological processes. Recent technical advances in the genome-wide determination of single-base DNA-methylation enabled epigenome-wide association studies (EWASs). Early EWASs established robust associations between age and gender with the degree of CpG methylation at specific sites. Other studies uncovered associations with cigarette smoking. However, so far these studies were mainly conducted in Caucasians, raising the question of whether these findings can also be extrapolated to other populations. Results: Here, we present an EWAS with age, gender, and smoking status in a family study of 123 individuals of Arab descent. We determined DNA methylation at over 450,000 CpG sites using the Illumina Infinium HumanMethylation450 BeadChip, applied state-of-the-art data processing protocols, including correction for blood cell type heterogeneity and hidden confounders, and eliminated probes containing SNPs at the targeted CpG site using 40× whole-genome sequencing data. Using this approach, we could replicate the leading published EWAS associations with age, gender and smoking, and recovered hallmarks of gender-specific epigenetic changes. Interestingly, we could even replicate the recently reported precise prediction of chronological age based on the methylation of only a few selected CpG sites. Conclusion: Our study supports the view that when applied with state-of-the art protocols to account for all potential confounders, DNA methylation arrays represent powerful tools for EWAS with more complex phenotypes that can also be successfully applied to non-Caucasian populations.

Original languageEnglish
Pages (from-to)7-6
Number of pages2
JournalClinical Epigenetics
Volume7
Issue number1
DOIs
Publication statusPublished - 25 Jan 2015

Fingerprint

DNA Methylation
Methylation
Smoking
Population
Genome
Biological Phenomena
Cytosine
Oligonucleotide Array Sequence Analysis
Epigenomics
Single Nucleotide Polymorphism
Blood Cells
Phenotype
Gene Expression

Keywords

  • Age
  • Association study
  • DNA methylation
  • Epigenetics
  • Gender
  • Smoking

ASJC Scopus subject areas

  • Genetics
  • Molecular Biology
  • Developmental Biology
  • Genetics(clinical)

Cite this

Association of dna methylation with age, gender, and smoking in an arab population. / Zaghlool, Shaza; Al-Shafai, Mashael; Al Muftah, Wadha A.; Kumar, Pankaj; Falchi, Mario; Suhre, Karsten.

In: Clinical Epigenetics, Vol. 7, No. 1, 25.01.2015, p. 7-6.

Research output: Contribution to journalArticle

Zaghlool, Shaza ; Al-Shafai, Mashael ; Al Muftah, Wadha A. ; Kumar, Pankaj ; Falchi, Mario ; Suhre, Karsten. / Association of dna methylation with age, gender, and smoking in an arab population. In: Clinical Epigenetics. 2015 ; Vol. 7, No. 1. pp. 7-6.
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