Cystic fibrosis (CF) is an inherited condition that affects the cells and glands that manufacture mucus, sweat and digestive enzymes. As a genetic disease, the origin or etiology of cystic fibrosis is a pair of defective genes. Individuals who have this disease have inherited one faulty cystic fibrosis gene from each parent. Initially, in the etiology of cystic fibrosis, a protein that controls the movement of salt in and out of cells is altered by the defective genes and becomes defective. Called the cystic fibrosis conductance transmembrane regulator (CFTR), this defective gene then causes the glands that control various secretions in the body to produce very thick and sticky secretions that plug up passageways, ducts and tubes in the body instead of acting as lubricants.
In order to have cystic fibrosis, a child must inherit one copy of the faulty CFTR gene from his or her mother and one from his or her father. Scientists estimate that if each of the parents passes the CFTR gene to the child, the child has about a 25 percent chance of developing cystic fibrosis. A child who inherits a faulty CFTR gene from only one parent most likely will simply be a carrier of the disease, will live a normal life and will not develop cystic fibrosis. Male and female children have an equal chance of inheriting this disease.
Cystic fibrosis is a chronic, progressive disorder. With the etiology of cystic fibrosis lying within the secretory gland system of the body, it is a disease that can have wide-ranging effects on the whole body. Although it most dramatically affects the lungs, cystic fibrosis might also cause significant problems in the sex organs, sinuses, liver, pancreas and intestines. In the lungs, this disease causes a thickened mucus to clog the airways and inhibit breathing. If it affects the pancreas and intestines, the individual will have problems absorbing nutrients from food.
Both the seriousness and symptoms of cystic fibrosis differ from one person to another. Some individuals might have significant problems with the lungs and digestive system and begin seeing a decline in lung function while they are small children. Others, though, might have a milder form that remains undiagnosed until adolescence or later.
Although various treatments are available, cystic fibrosis is a life-threatening disease that dramatically shortens the lifespan of individuals who have the condition. Scientists estimate that there are more than 1,400 possible mutations of the CTFR gene that can produce cystic fibrosis. For this reason, determining the etiology of cystic fibrosis with precision is very difficult.