<p>Cystic fibrosis (CF) is the most common lethal genetic disorder affecting Caucasian populations, particularly those of northern European origin. It is a hereditary disease affecting cells of the exocrine glands. The faulty gene responsible is recessive and has been identified as lying on chromosome number 7. Affected individuals lack the protein that enables transport of chloride ions across cell membranes. This results in the production of thick mucus which obstructs the intestinal glands, pancreas and bronchi. Currently, the average age at death is 31 years.</p>