In a study of 111 families funded by the National Institutes of Health found a genetic link between smoking and the lung disorder that kills about half its victims within five years of diagnosis.
"Independent of genes, cigarette smoking also contributes to the development of this disease. The next step is to identify the specific gene or genes that cause the disease," said Mark Steele, lead researcher of the Duke University Medical Center.
Idiopathic interstitial pneumonia is often accompanied by scarring and inflammation of the lungs known as pulmonary fibrosis. Pulmonary fibrosis affects about 100,000 U.S. residents.
"It once again underscores why people should not smoke," said David Schwartz, director of the National Institute of Environmental Health Sciences.
The study was published in the American Journal of Respiratory and Critical Care.