Lung disease progression is variable among cystic fibrosis (CF) patients and depends on DNA mutations in the CFTR gene, polymorphic variations in disease-modifier genes and environmental exposure. The contribution of genetic factors has been extensively investigated, whereas the mechanism whereby environmental factors modulate the lung disease is unknown. Because these factors can affect the epigenome, investigators hypothesized that DNA methylation variations at disease-modifier genes modulate the lung function in CF patients.

Lung disease progression is variable among cystic fibrosis (CF) patients and depends on DNA mutations in the CFTR gene, polymorphic variations in disease-modifier genes and environmental exposure. The contribution of genetic factors has been extensively investigated, whereas the mechanism whereby environmental factors modulate the lung disease is unknown. Because these factors can affect the epigenome, investigators hypothesized that DNA methylation variations at disease-modifier genes modulate the lung function in CF patients.

The investigators analyzed DNA methylation levels in the promoter of fourteen lung disease-modifier genes and showed that DNA methylation levels are altered in nasal epithelial and blood cell samples from CF patients. This study disclosed slightly, but significantly differentially methylated regions that collectively may modulate lung disease severity. It also highlighted that complex relationships between genetic and epigenetic factors contribute to the phenotypic variability of CF patients.

Inclusion Criteria:

• >18 years old
• homozygous for the F508del mutation

Exclusion Criteria:

• subjects who have an active CF exacerbation or a recent viral infection on the day of biological samples collection;
• pregnant women;
• patients who are included in interventional medical trials;
• patients who had lung transplantation.