The Frequency and Potential Implications of HFE Genetic Variants in Children With Cystic Fibrosis

Genetic modifiers have been identified that increase the risks of lung disease and other complications, such as diabetes in people with cystic fibrosis (CF). Variants in the hemochromatosis gene (HFE) were reported in a study of adults to be associated with worse lung disease.

To ascertain the frequency of HFE variants, particularly C282Y (c.845G > A) and H63D (c.187C > G) and to determine if they are associated with variations in the onset and early severity of CF lung disease as well as abnormalities in iron status.

We studied with whole genome sequencing and clinical outcome measures in a cohort of 104 children with CF at 5-6 years old who were previously found to show an association between aggregated genetic modifiers and an earlier onset and a more severe lung disease phenotype.

In our cohort, 23% have H63D and 11% have C282Y. Lung function at age 6 years and Pseudomonas aeruginosa infections did not differ by HFE variants, but having C282Y was associated with more pulmonary exacerbations in the first 6 years of life. Three patients have H63D/C282Y genotype, and all showed phenotypic expression of hemochromatosis with abnormal iron indices.

Our study revealed that the presence of HFE variant C282Y in people with CF may lead to more severe lung disease manifestations beginning in early childhood. There is a risk of hemochromatosis in CF patients with two HFE variants, and thus they should be followed for evidence of iron overload.