One of the most common causes of childhood death is the chronic disease of Cystic Fibrosis. Cystic Fibrosis is a generalized dysfunction of the exocrine glands that affects multiple organ systems.
The gene responsible for cystic fibrosis encodes a protein that involves chloride transport across epithelial membranes. Over 100 mutations of the gene are known. The passing of the gene can only occur if both parents are carriers of the gene. Symptoms such as increased viscosity of bronchial, pancreatic, and other mucous gland secreations and consequent obstructions of glandular ducts are immediate symptoms in Cystic Fibrosis (CF).

If both mother and father carry a gene
for CF, some sperms and some eggs will
carry the abnormal gene. If a carrier
sperm and a carrier egg unite, the child
will have CF. A carrier sperm uniting
with a normal egg, or vice-versa, will
produce a carrier child. If both uniting
sperm and egg are normal, the child
will be normal.

In the United States, CF is found most in Whites of Northern European Ancestry (1 in 2,000- 5,000 live births). And the incidence of CF is lowest in Blacks, Native Americans and people of Asian ancestry. CF is found equally throughout males and females.
Clinical effects of CF can become apparent soon after birth, or can be disguised for years. The most consistent of symptoms is sweat gland dysfunction, and others include respitory and GI function. Thick sticky mucus clogging the lungs, a blocked pancreas, poor circulation, and the inability to absorb nutrients from food are just some of the other problems caused by the disease. Also, some signs of CF can be increased concentrations of sodium and chloride in the sweat, and respitory symptoms such as wheezy respirations and a dry, nonproductive, paroxysmal cough.
In children, CF causes a barrel chest, cyanosis, and clubbing of the fingers and toes. They suffer recurring bronchitis and pneumonia and also associated nasal ployps and sinusitis. Cystic Fibrosis usually causes death from recurring pneumonia or emphysema.
In treatment of CF patients, a special low fat diet is essential. To combat the electrolyte losses in sweat, much salt is needed in the diet. In hot weather, a CF patient is to administer sodium supplements. Modern antibiotics and nursing care have made it possible for some patients to survive repeated pneumonia. With improvements in treatment over the last decade, the average life expectancy has risen from age 16 to 25 and more. Hospital units now specialize in the care for patients with the Cystic Fibrosis disease.
For many parents, if one child has Cystic Fibrosis, there is a 25% chance of any more of the same parents offspring to have the disease. 50% chance that the baby would be a carrier, and a 25% chance that the baby would be normal.
The best way to prevent the passing of the CF gene to your offspring is to take a CF carrier test. If mother and father are both carriers for the gene of Cystic Fibrosis, they are at a 90% chance to have a CF baby.