As the above writeup mentions, CF is a recessive genetic disorder most commonly found in caucasians. One in 28 whites carries a copy of the gene responsible for the disease.

The way the disease actually works, according to WebMD, is by affecting the way water and salt are moved into and out of mucus-producing cells. The upshot is that all systems with a large number of mucus-producing cells are affected, including the respiratory, digestive, exocrine and reproductive systems.

The majority of cases are diagnosed in the first year of life. The most common first symptom noticed in babies is intestinal blockage. Other symptoms that are often noticed early are fatty, foul-smelling stools, failure to grow, and a persistent cough or lung problems. After symptoms are noticed, the sweat test is used to confirm CF. Particularly mild cases may not be noticed until later in life, when symptoms gradually worsen. Some cases are not diagnosed until early adulthood, although this is rare.

Because the body has so many systems which produce mucus, the disease affects several different functions:

Digestion: Because CF patients have extraordinary amounts of mucus in their digestive tracts, nutrient absorption is impaired. Malnourishment can result, even at above-average levels of caloric intake.

Reproduction: One of the more common results of CF is infertility. Even sufferers with very mild forms of CF may find themselves sterile, even those who exhibit no other symptoms.

Respiration: Over time, mucus buildup in the lungs destroys healthy tissue. CF patients generally are more susceptible to respiratory infections, and take a longer time to heal. As time goes on, the lungs eventually become severely damaged. Inefficient respiration also leads to enlargement of the right side of the heart, called cor pulmonale. The two most common causes of death in CF patients are heart failure and lung infections.

Many CF patients don't make it to adulthood. The average life expectancy is only 30 years, although new treatments are starting to increase that number. Treatments include antibiotics to prevent respiratory infections, nutritional and enzyme supplements, and percussion to loosen mucus in the lungs. In some cases, lung transplants or heart-lung transplants may be used to extend the lifespan. There are also several gene-therapy trials currently underway to try to cure or lessen the impact of CF.