Diffuse lung disease: product of genetic susceptibility and environmental encounters.

Diffuse (interstitial) lung disease comprises a wide variety of conditions, individually relatively uncommon but collectively being found in approximately 50 per 100,000 population. Some of these diseases are of known aetiology but others are not. It has been suggested that the environment is a major contributory factor in this group of diseases. However, since not all individuals exposed to a common environment develop interstitial diseases, it can be hypothesised that there is a genetic predisposition to their development. These diseases cause major morbidity and mortality due to lung injury and fibrosis. It follows that, if individuals who are genetically predisposed to develop diseases characterised by lung injury and fibrosis can be identified, then management strategies can be designed which will attempt to identify and treat early disease and, in the longer term, to develop targeted genetic interventional approaches to treatment.