The influence of genetics on smoking

A new study from Yale University reveals genetic markers that could predict which people are more likely to start smoking and quit compared to others.

The study was published in the journal Nature on October 20 and was co-authored by Yale School of Medicine psychiatry professor Ke Xu and biostatistics doctoral student Boyang Li. The researchers identified 99 genetic variants linked to smoking initiation and 13 variants linked to smoking cessation. The research was funded by the U.S. Department of Veterans Affairs and was part of its Million Veteran Program.

A study conducted on veterans

More than 825,000 veterans have participated in the program, which aims to understand how genetic and environmental factors affect individual health.

Researchers Xu and Li compared the highly diverse genomes of these individuals. With this large cohort, they were able to access data collected over a long period of time on the patients' smoking histories. They then identified loci of genetic variation that may be linked to the likelihood that a patient will smoke or not.

The interest in this study lies in the fact that once certain genetic markers that increase the likelihood that an individual will smoke are identified, it becomes possible to more effectively treat people with these risk factors in a more targeted manner.

One factor among others

While the study focuses on how a person's genetics affect their smoking behavior, Dr. Xu said genes are not the only factor determining smoking prevalence or cessation. The genetic influence of smoking is thought to be about 40 to 50%, meaning other environmental factors play a role (education or smoking-related policy such as taxes or regulations, among others).

Genetics therefore contribute significantly to the risk of smoking without being the only determinant. Antonio Giraldez, chairman of the university's genetics department, says that the next step in this research is to reproduce the study with another large cohort, to refine the results.