[Cystic fibrosis modifying genes]

Cystic fibrosis is a common autosomal recessive disease that is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR gene encodes a membrane-bound chloride ion channel. CFTR gene mutations cause alterations in fluid and salt secretion of various tissues. The CF phenotype is highly variable even in siblings and twins carrying the same CFTR mutations. The course of CF pulmonary disease is modulated by both environmental and genetic factors independent of CFTR. This review summarises association studies that focused on disease modifier genes in CF. Understanding the molecular and cellular basis of the genotype-phenotype associations will help to better understand the disease and to identify new targets for therapeutic interventions in CF.