title: Biological and methodological aspects of assessment of locus specific de novo methylation in blood.
abstract: OBJECTIVE
  Locus-specific methylation in blood differs between individuals. As those changes may represent de novo methylation, induced by environmental factors, we aimed to evaluate the biological and methodological limitations of detection of methylation in blood.
  
  
  METHODS
  We used Methylation-Sensitive High Resolution Melting to analyze methylation at 21 gene loci in peripheral blood DNA samples from 203 healthy women.
  
  
  RESULTS
  Overall nine of the screened loci displayed marked inter-individual variation in methylation frequency with methylation levels predominantly around 1%. The methylation of specific loci showed different association with age and reproducibility of detection.
  
  
  CONCLUSIONS
  Our results allowed benchmarking of both technological and biological limitations that need to be accounted for when evaluating locus specific methylation in blood as potential biomarker.
authors.affiliation: Institute of Environmental Medicine (Unit for Metals & Health), Karolinska Institutet, Nobels vag 13, Box210, 17177 Stockholm, Sweden.
authors.forename: Tomasz Kazimierz
authors.initials: TK
authors.lastname: Wojdacz
mesh_terms: D000367:Age Factors; D001769:Blood / Q000378:metabolism*; D019175:DNA Methylation / Q000235:genetics*; D005260:Female; D056426:Genetic Loci; D006801:Humans; D009691:Nucleic Acid Denaturation; D015203:Reproducibility of Results; D017422:Sequence Analysis, DNA
keywords: biomarker; environment; exposure; methylation