While some diseases, such as cystic fibrosis, are almost wholly genetic, genetic factors play a role in making us more or less vulnerable to the whole spectrum of respiratory disease.
The search for genetic links to disease is two-pronged: linkage studies begin with a disease and look for genes associated with it, while association studies begin with polymorphisms or mutations, and look for associations with disease.
Several genes have been identified that influence susceptibility to both asthma and COPD, reflecting similarities in disease presentation between the two conditions.
Nondisease traits that influence respiratory health, such as tendency to nicotine addiction, and lung function, have also been related to genetic variations.
See the entire Genetic Susceptibility Chapter