Each time two people carrying the CF gene conceive a child, there is a 25-percent chance the child will be born with the disease, a 50-percent chance that the child will be a carrier, and a 25-percent chance that the child will be a non-carrier.

The disease, which is not contagious, usually is diagnosed in early childhood. The most reliable diagnostic test is the "sweat test," aptly named because most cystic fibrosis patients have skin that is salty to the taste. Other common symptoms of CF include chronic cough and difficulty breathing, frequent sinus and respiratory infections, excessive production of mucus, recurrent pneumonia, and digestive problems. Children born with CF do not have a normal life expectancy, though it is improving all the time. The median life expectancy is just under 30 years.

The daily rigors of living with cystic fibrosis are tough both on the people afflicted with the disease and on their families. Fortunately, a combination of therapy and pharmaceuticals can help keep the symptoms under control and enhance the person's quality of life. Cystic fibrosis is treated using: daily antibiotics and anti-inflammatory medication; several inhalation treatments each day to cut through the thick mucus and expand the airways; high doses of intravenous antibiotics during bacterial infections; daily therapy sessions to loosen and promote drainage of the mucus; enzyme pills with food that help in digestion; and proper nutrition and vitamins. Even with the extensive treatment regimen, breathing remains difficult.

Despite thorough treatment and care, thick mucus and recurrent infections will eventually damage the lungs beyond repair. It is at this advanced stage that a lung transplant becomes necessary.