On Sept. 2008, a narrow region on chromosome 15 contains genetic variations strongly associated with familial lung cancer, says a study conducted by scientists at Washington University School of Medicine in St. Louis and other institutions in the U.S. and UK.

The researchers found a more than five times higher risk of lung cancer for people who have both a family history of the disease and these genetic variations. The risk was not affected by whether the study participants smoked or didn’t smoke.

This study was the fourth since April 2008 to implicate this genetic region in the development of lung cancer, and it strengthens the possibility that testing for variations in this region could become a valuable way to warn individuals of their higher risk. The study results were published in the Journal of the National Cancer Institute.