Cystic fibrosis (CF) is a genetically inherited and potentially fatal disease. In the Western world, 1 in 23 people carry the defective gene. This article outlines the genetics of CF and its mode of inheritance and examines what types of carrier screening are available. The carrier frequency is calculated using the Hardy-Weinberg equilibrium. Current treatments are evaluated, with a description and critique of gene therapy, the treatment of the future for respiratory failure.