title: A polymorphism in the TH 2 locus control region is associated with changes in DNA methylation and gene expression.
abstract: BACKGROUND
  Genomewide association and epigenetic studies found a region within the RAD50 gene on chromosome 5q31 to be associated with total serum IgE levels and asthma. In mice, this region harbors a locus control region for nearby TH 2 cytokines, which is characterized by four Rad50 DNase I hypersensitive sites (RHS4-7). Among these, RHS7 seems to have the strongest impact on TH 2 differentiation. We investigated whether within the human homolog of RHS7, functional polymorphisms exist, which could affect DNA methylation or gene expression in the 5q31 locus and might have an influence on asthma status or IgE regulation.
  
  
  METHODS
  The human RHS7 region was fine mapped using 1000 genomes database information. In silico analysis and electrophoretic mobility shift assays were used to assess SNP function. Allele-specific effects on DNA methylation were evaluated in cord blood (n = 73) and at age of 4.5 years (n = 61) by pyrosequencing. Allele-specific effects on RAD50, IL4, and IL13 expression were analyzed in 100 subjects. Associations with asthma and IgE levels were investigated in the MAGICS/ISAAC II population (n = 1145).
  
  
  RESULTS
  Polymorphism rs2240032 in the RHS7 region is suggestive of allele-specific transcription factor binding, affects methylation of the IL13 promoter region and influences RAD50 and IL4 expression (lowest P = 0.0027). It is also associated with total serum IgE levels (P = 0.0227).
  
  
  CONCLUSIONS
  A functional relevant polymorphism in the TH 2 locus control region, equivalent to RHS7 in mice, affects DNA methylation and gene expression within 5q31 and influences total serum IgE on the population level.
authors.affiliation: Department of Pediatric Pneumology and Allergy, University Children`s Hospital Regensburg (KUNO), Regensburg, Germany; Department of Pediatric Pneumology, Allergy and Neonatology, Hannover Medical School, Hannover, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schieck
authors.forename: V
authors.initials: V
authors.lastname: Sharma
authors.forename: S
authors.initials: S
authors.lastname: Michel
authors.forename: A A
authors.initials: AA
authors.lastname: Toncheva
authors.forename: L
authors.initials: L
authors.lastname: Worth
authors.forename: D P
authors.initials: DP
authors.lastname: Potaczek
authors.forename: J
authors.initials: J
authors.lastname: Genuneit
authors.forename: A
authors.initials: A
authors.lastname: Kretschmer
authors.forename: M
authors.initials: M
authors.lastname: Depner
authors.forename: J-C
authors.initials: JC
authors.lastname: Dalphin
authors.forename: J
authors.initials: J
authors.lastname: Riedler
authors.forename: R
authors.initials: R
authors.lastname: Frei
authors.forename: J
authors.initials: J
authors.lastname: Pekkanen
authors.forename: J
authors.initials: J
authors.lastname: Tost
authors.forename: M
authors.initials: M
authors.lastname: Kabesch
mesh_terms: D017766:Acid Anhydride Hydrolases; D000328:Adult; D001249:Asthma / Q000235:genetics* / Q000276:immunology; D002648:Child; D019175:DNA Methylation / Q000276:immunology; D045643:DNA Repair Enzymes / Q000235:genetics / Q000276:immunology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000276:immunology; D024202:Electrophoretic Mobility Shift Assay; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology*; D055106:Genome-Wide Association Study; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D018793:Interleukin-13 / Q000235:genetics / Q000276:immunology; D019901:Locus Control Region / Q000235:genetics* / Q000276:immunology; D008297:Male; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D004268:DNA-Binding Proteins; D018793:Interleukin-13; D007073:Immunoglobulin E; D017766:Acid Anhydride Hydrolases; C112158:RAD50 protein, human; D045643:DNA Repair Enzymes
keywords: 5q31; IgE; RAD50; epigenetics; locus control region