Cystic fibrosis is a genetic disorder characterized by the build-up of mucus that is abnormally thick and sticky on the linings of organs such as the esophagus and lungs. It is caused by a mutation in the gene called CFTR (cystic fibrosis transmembrane regulator), a gene responsible for regulating ions of the cell membranes in the linings of the lungs and esophagus.
>>> Cystic fibrosis is caused by a mutation in the gene that regulates ion movement across the cell membrane.