Drop into any support group meeting, and you'll likely find that many of the addicts there had a parent who was also an addict. It's estimated that alcoholism (now sometimes called alcohol-use disorder) is 50 percent heritable, although researchers have struggled to identify genes specifically associated with the condition.
The hunt continues for alcohol-use disorder related genes, and a new frontier in the field is the study of the epigenome, a term that refers to inherited changes that affect gene expression, rather than the genes themselves. A new review by a team based at the University of Pittsburgh School of Medicine in the journal Alcohol compiles all that is known about the effects of the epigenome on alcohol inheritance.
"Only recently, with improvements in technology to identify epigenetic modifications in germ cells, has it been possible to identify mechanisms by which paternal ethanol (alcohol) exposure alters offspring behavior," the researchers wrote.
The basic mechanism is that traits can be passed on through modification of the proteins associated with DNA; these proteins control how genes are expressed. Several studies have examined the role of a father's alcohol use in the time period surrounding conception, finding their children more likely to suffer from some psychiatric disorders; in research on mice, some effects of paternal alcohol use include low birth weight and decreased grooming. These effects are likely attributed to the alteration of the development of sperm, the researchers write.
Many mysteries remain, leaving plenty of opportunities for additional research. Now, the team is starting to examine how paternal exposure affects offspring's alcohol consumption.
Previously: Alcoholism: Not just a man's problem, Could better alcohol screening during doctor visits reduce underage drinking? and Are some teens' brains pre-wired for drug and alcohol experimentation?
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