Cystic fibrosis (CF) is an inherited disease that is present from birth, although symptoms may not appear for weeks, months, or even years after birth.
CF is caused by a defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The abnormality in the gene affects the way in which sodium and water move in and out of the body’s cells. The water and sodium help the body to produce thin, slippery mucus. Mucus is a slippery substance that lubricates the linings of the airways, reproductive system, digestive system and some organs and bodily tissues.
Cystic Fibrosis (CF) causes the body to produce thick mucus that can block small ducts and tubes throughout the body, especially in the lungs and pancreas. The abnormally thick mucus causes a variety of complications including airway obstruction, bacterial infections, lung damage, digestive difficulties and a variety of other problems.
More than 1,000 mutations in the CFTR gene have been identified in individuals with CF. The severity of CF depends on which particular mutation the gene has suffered. The mutations in the CFTR gene can alter the organization or stability of the cell. These changes or mutations impair the movement of the water and salt in and out of cells. These mutations in the CFTR gene will result in thick, sticky mucus. The abnormal mucus obstructs airways, ducts, tubes and glands, leading to the characteristics of cystic fibrosis.
The affected CFTR gene is inherited from a child’s parent and is a recessive gene. With recessive genes, children need to inherit two copies of the affected gene, one from each parent. If a child inherits one affected gene from one parent and one unaffected gene from the other parent, they will not have CF but they will be carriers of CF. Individuals who are carriers of CF are healthy and exhibit no signs or symptoms.
If two people who do not have CF but carry the defective gene conceive a child:
- 25 percent chance the child will have CF
- 50 percent chance the child will be a carrier
- 25 percent chance the child will not be a carrier and not have CF
There currently is no cure for CF; however, researchers are working hard to develop new medications and to find a way to replace the defective CFTR gene. With medications, chest therapy and exercise, individuals with CF are able to live happy productive lives.
