Researchers Suspect Genetic

They studied 7,691 participants in the Framingham Heart Study in an attempt to identify a relationship between common genetic variants and measures of lung function. This led them to gene variants on chromosome 4 that could be a potential risk factor for the disease, known as COPD.

"Several interesting genes are present in the region that we identified, including a gene (HHIP) interacting with a biological pathway involved in lung development, but it is not yet clear which gene in the region explains the association," lead author Jemma Wilk, an assistant professor of neurology, said in a university news release.

"Our results identified a region of chromosome 4 that warrants further study to understand the genetic effects influencing lung function," Wilk said.

The study appears March 20 in PLoS Genetics.

COPD is a lung disease that's the fourth-leading cause of death in the United States and one of the leading disease-related causes of disability in adults. Cigarette smoking is the primary risk factor for COPD, but just 20 percent of smokers develop the condition. This fact, along with family studies of lung function and COPD, suggest that genetic factors affect a person's susceptibility to cigarette smoke, according to background information from the researchers.