Cystic fibrosis is a genetic disorder that causes thick mucus to build up in the respiratory system and in the pancreas. People with cystic fibrosis are highly susceptible to respiratory infections and are typically malnourished due to the malfunctioning of the pancreas. In the United States, the disease affects about one in every 3,900 babies born annually; currently 30,000 Americans are afflicted with this disease. The genetic defect that causes cystic fibrosis is most common in people of northern European descent. It is estimated that one in 31 Americans carries the gene for cystic fibrosis. No cure for cystic fibrosis exists, and the disease is invariably fatal. Only 50% of people with the disease survive into their 30s. Ninety-five percent of cystic fibrosis deaths are caused by lung complications; the other 5% are due to liver failure.

Cystic fibrosis is a homozygous recessive genetic disorder. In this type of disorder two...