About 30 percent of nonsmokers who develop lung cancer have an unusual variant of a gene called GPC5 that may make them more vulnerable to the disease, according to researchers.

The Owens Sound Times reported March 22 that about one in four lung-cancer patients are nonsmokers, meaning they have consumed fewer than 100 cigarettes in their lifetime. Among women, slightly more than half of lung-cancer patients have never smoked.

Researchers said that the faulty GPC5 gene may not properly suppress tumor growth.

The study was published in the March 22, 2010 issue of the journal Lancet Oncology.