A son is more likely to consume large amounts of alcohol if his father is a chronic drinker.

A new study has discovered that even before conception, a son’s vulnerability to alcohol consumption is potentially shaped by a father who chronically drinks. This study could provide insight into how alcohol abuse can be an inherited trait, and how this trait affects drinking behaviors in offspring.

Senior study investigator Gregg E. Homanics, Ph.D. of the Pitt School of Medicine and his colleagues consistently exposed male mice over a five-week period to intermittent ethanol vapor, which lead to blood alcohol levels that were slightly higher than the legal limit for driving. The male mice then mated with female mice who were not exposed to alcohol.

“We examined whether a father’s exposure to alcohol could alter expression of the genes he passed down to his children. Rather than mutation of the genetic sequence, environmental factors might lead to changes that modify the activity of a gene, which is called epigenetics. Our mouse study shows that it is possible for alcohol to modify the dad’s otherwise normal genes and influence consumption in his sons, but surprisingly not his daughters,” said Homanics in a statement.

Previous studies on humans did indicate that alcoholism runs in the family, especially from father to son, yet only a few gene variants have been linked with the alcoholism to date.

The findings of the study are published online in PLOS ONE.