What is Cystic Fibrosis (CF)?

Cystic Fibrosis Center

What is Cystic Fibrosis (CF)?

Cystic fibrosis (CF) is an inherited (genetic) disease, meaning that children who have cystic fibrosis are born with the disease even though they may not show signs of the disease until they are older.

Cystic fibrosis is also a chronic illness. Until there is a cure, the person will have cystic fibrosis for his/her entire life.

The Problem

People with cystic fibrosis have an abnormality in the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR is a chloride channel that controls the way body salts (sodium and chloride) and water move into and out of the body's cells.

In a person with cystic fibrosis, the CFTR does not work properly and causes the body to produce abnormally thick, sticky mucus. The organs most affected by this defect are the lungs, pancreas, sweat glands and those within the reproductive system.

How common is cystic fibrosis?

Cystic fibrosis is the most common genetic disease in white people. It affects about 30,000 children and adults in the United States and about 70,000 people worldwide.

Although cystic fibrosis is more commonly found in the white population, the disease affects all racial groups. Cystic fibrosis occurs in about one in every 3,500 white births, one in every 17,000 black births, and one in every 90,000 Asian births. About 12 million people (about one in 30 people) in the United States carry one cystic fibrosis gene mutation.

Signs and Symptoms

The most common signs of cystic fibrosis are:

  • Salty-tasting sweat
  • Chronic cough
  • Frequent lung infections
  • Poor weight gain
  • Frequent loose stools

The onset of symptoms can vary. Some infants show symptoms soon after birth. For example, some babies are born with meconium ileus, a blockage in the intestines. Other children do not develop symptoms until they are much older.

People with cystic fibrosis do not have identical symptoms. Some have more digestive involvement while their lungs seem unaffected. Others have respiratory symptoms and normal digestion. Some people have respiratory and digestive symptoms while others show no signs of cystic fibrosis except for salty-tasting sweat.

The severity of symptoms also varies from one person to another. Some children develop lung infections that require hospitalization early in life while others remain healthy for many years.