Cystic Fibrosis Conductance Transmembrane Regulator is a protein involved in the transport of chloride ions across cell membranes or the gene that encodes this protein
CFTR is a ABC transporter-class ion channel that transports chloride and thiocyanate ions across epithelial cell membranes. Mutations of the CFTR gene affect functioning of the chloride ion channels in these cell membranes, leading to cystic fibrosis and congenital absence of the vas deferens.
Well over one thousand mutations have been described that can affect the CFTR gene. Such mutations can cause two genetic disorders, congenital bilateral absence of vas deferens and the more widely known disorder cystic fibrosis. Both disorders arise from the blockage of the movement of ions and, therefore, water into and out of cells. In congenital bilateral absence of vas deferens, the protein may be still functional but not at normal efficiency, this leads to the production of thick mucus, which blocks the developing vas deferens. In people with mutations giving rise to cystic fibrosis, the blockage in ion transport occurs in epithelial cells that line the passageways of the lungs, pancreas, and other organs. This leads to chronic dysfunction, disability, and a reduced life expectancy.
The most common mutation, ΔF508 results from a deletion (Δ) of three nucleotides which results in a loss of the amino acid phenylalanine (F) at the 508th position on the protein. As a result the protein does not fold normally and is more quickly degraded.