The Influence of Genetics on

Technological advances in genetics have made feasible and affordable large studies to iden-tify genetic variants that cause or modify a trait. Genetic studies have been carried out to assess variants in candidate genes, as well as polymorphisms throughout the genome, for their associations with heritable clinical outcomes of cystic fibrosis (CF), such as lung disease, meconium ileus, and CF-related diabetes. The candidate gene approach has iden-tified some predicted relationships, while genome-wide surveys have identified several genes thatwould not have been obvious disease-modifying candidates, such as amethionine sulfoxide transferase gene that influences intestinal obstruction, or a region on chromosome 11 proximate to genes encoding a transcription factor and an apoptosis controller that associates with lung function. These unforeseen associations thus provide novel insight into disease pathophysiology, as well as suggesting new therapeutic strategies for CF. Cystic fibrosis (CF) is a Mendelian “mono-genic ” recessive genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (Welsh et al. 2001). There is a broad range of age-of-onse