Cystic Fibrosis - Causes

Cystic fibrosis is a genetic disorder. Genes are the chemical units in every cell that tell cells what functions they should perform and what substances they should manufacture in order to operate normally. Genes can be damaged in a variety of ways. For example, certain chemicals contained in the foods we eat can damage a gene. When that happens, the gene is no longer able to give correct instructions to a cell and the cell does not have the information it needs to produce all the substances it requires to stay healthy. When this happens, a medical problem develops in some part of the body.

Genes are passed down from one generation to the next. A person whose body contains a damaged gene may pass that gene to his or her children. The children may develop the same genetic disorder that the parent had.

Cystic fibrosis is caused by a defect in the gene known as the CFTR gene. The abbreviation CFTR stands for cystic fibrosis transmembrane conductance regulator. The CFTR gene carries instructions for the production of mucus in cells. Mucus is a mixture of water, salts, sugars, and proteins. Its job is to cleanse, lubricate, and protect passageways in the body.

Cells that contain a defective CFTR gene have lost the ability to make mucus properly. The mucus they produce has too little water in it and is thick and syrupy. This mucus does not improve the functioning of passageways in the body. Instead, it causes them to become clogged. Substances that are supposed to pass through passageways, such as air and blood, are unable to flow normally and the symptoms of CF begin to appear.