F508del homozygous cystic fibrosis patients and healthy controls

Using the 450K BeadChIP, we profiled DNA methylation in nasal epithelial cells collected from CF patients homozygous for the CFTR p.Phe508del mutation and healthy controls. We replicated DNA methylation at CpG sites by pyrosequencing. Patients were stratified according to their lung function (forced expiratory volume in 1 second). Our study (i) points to the importance of genes responsible for the integrity of the epithelium and the inflammatory and immune responses to explain lung disease variability in CF, (ii) highlights new candidate genes potentially involved in lung disease severity, while it corroborates the role of known modifier genes, and (iii) suggests that CF-associated dynamic changes of DNA methylation are prominent in transcriptionally active genomic regions. Bisulphite converted DNA from the 48 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip 32 cystic fibrosis patients (16 mild , 8 intermediary, 8 severe lung disease) and 16 healthy controls