title: Cow's milk allergy in Dutch children: an epigenetic pilot survey.
abstract: BACKGROUND
  Cow's milk allergy (CMA) is a common disease in infancy. Early environmental factors are likely to contribute to CMA. It is known that epigenetic gene regulation can be altered by environmental factors. We have set up a proof of concept study, aiming to detect epigenetic associations specific with CMA.
  
  
  METHODS
  We studied children from the Dutch EuroPrevall birth cohort study (N = 20 CMA, N = 23 controls, N = 10 tolerant boys), age and gender matched. CMA was challenge proven. Bisulfite converted DNA (blood) was analyzed using the 450K infinium DNA-methylation array. Four groups (combined, girls, boys and tolerant boys) were analysed between CMA and controls. Statistical analysis and pathway-analysis were performed in "R" using IMA, Minfi and the global-test package. Differentially methylated regions in DHX58, ZNF281, EIF42A and HTRA2 genes were validated by quantitative amplicon sequencing (ROCHE 454(®)).
  
  
  RESULTS
  General hypermethylation was found in the CMA group compared to control children, while this effect was absent in the tolerant group. Methylation differences were, among others, found in regions of DHX58, ZNF281, EIF42A and HTRA2 genes. Several of these genes are known to be involved in immunological pathways and associated with other allergies.
  
  
  CONCLUSIONS
  We show that epigenetic associations are involved in CMA. Although, the statistical power of our study is limited and our sample was based on whole blood, we were still able to detect feasible loci and pathways. Therefore our findings might contribute to future diagnostic or therapeutic interventions for specific CMA. Further studies have to confirm the findings of our study.
authors.affiliation: Department of Pediatric Respiratory Medicine and Allergy, H7-270, Emma Children's Hospital Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Nicole C M
authors.initials: NCM
authors.lastname: Petrus
authors.affiliation: Department of Clinical Genetics, DNA-Diagnostics Laboratory, Amsterdam Medical Center, Amsterdam, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Henneman
authors.affiliation: Department of Clinical Genetics, DNA-Diagnostics Laboratory, Amsterdam Medical Center, Amsterdam, The Netherlands.
authors.forename: Andrea
authors.initials: A
authors.lastname: Venema
authors.affiliation: Department of Clinical Genetics, DNA-Diagnostics Laboratory, Amsterdam Medical Center, Amsterdam, The Netherlands.
authors.forename: Adri
authors.initials: A
authors.lastname: Mul
authors.affiliation: Department of Clinical Genetics, DNA-Diagnostics Laboratory, Amsterdam Medical Center, Amsterdam, The Netherlands.
authors.forename: Femke
authors.initials: F
authors.lastname: van Sinderen
authors.affiliation: Department of Clinical Genetics, DNA-Diagnostics Laboratory, Amsterdam Medical Center, Amsterdam, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: Haagmans
authors.affiliation: Department of Clinical Genetics, DNA-Diagnostics Laboratory, Amsterdam Medical Center, Amsterdam, The Netherlands.
authors.forename: Olaf
authors.initials: O
authors.lastname: Mook
authors.affiliation: Department of Pediatric Respiratory Medicine and Allergy, H7-270, Emma Children's Hospital Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.|Department of Clinical Genetics, DNA-Diagnostics Laboratory, Amsterdam Medical Center, Amsterdam, The Netherlands.
authors.forename: Raoul C
authors.initials: RC
authors.lastname: Hennekam
authors.affiliation: Department of Pediatric Respiratory Medicine and Allergy, H7-270, Emma Children's Hospital Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Aline B
authors.initials: AB
authors.lastname: Sprikkelman
authors.affiliation: Department of Clinical Genetics, DNA-Diagnostics Laboratory, Amsterdam Medical Center, Amsterdam, The Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: Mannens
keywords: Cow’s milk allergy; Epigenetics; Food allergy; Gender differences; Tolerant