By Robert Preidt
FRIDAY, Jan. 18, 2019 (HealthDay News) -- Do you shy away from risky business or cast caution aside and go for it?
Either way, your answer could come from your DNA.
Scientists have identified more than 100 genetic variants linked with risk-taking, according to a groundbreaking new study.
"Genetic variants that are associated with overall risk tolerance -- a measure based on self-reports about individuals' tendencies to take risks in general -- tend to also be associated with more speeding, drinking, tobacco and cannabis consumption, and with riskier investments and sexual behavior," said the study's corresponding author Jonathan Beauchamp. He's an assistant professor of economics at the University of Toronto, Canada.
"We also found shared genetic influences on overall risk tolerance and several personality traits and neuropsychiatric traits -- including ADHD [attention-deficit/hyperactivity disorder], bipolar disorder and schizophrenia," he added in a university news release.
While individual effects of each of the 124 identified genetic variants in 99 separate regions of the genome are small, their combined impact can be significant, the researchers explained.
"The most important variant explains only 0.02 percent of the variation in overall risk tolerance across individuals. However, the variants' effects can be combined to account for greater variation in risk tolerance," Beauchamp said.
His team created a "polygenic score" that rates the combined effects of 1 million genetic variants and accounts for about 1.6 percent of differences in risk tolerance from person to person.
"I expect it to be useful in social science studies," Beauchamp said. "For instance, the score can be used to study how genetic factors interact with environmental variables to affect risk tolerance and risky behaviors."
But the score can't meaningfully predict a particular person's tolerance for risk or risk-taking behavior, according to the authors of the study published Jan. 14 in the journal Nature Genetics.
The study -- one of the largest ever -- included genetic information from more than 1 million people with European ancestry, the researchers said.
The investigators found no evidence to support previously reported links between risk tolerance and certain genes, such as those associated with dopamine or serotonin, neurochemicals involved in the processing of rewards and mood regulation.
Instead, the new findings suggest that the neurochemicals glutamate and GABA contribute to individual differences in risk tolerance. Both are important regulators of brain activity.
"Our results point to the role of specific brain regions -- notably the prefrontal cortex, basal ganglia, and midbrain -- that have previously been identified in neuroscientific studies on decision-making," Beauchamp said.
"They conform with the expectation that variation in risk tolerance is influenced by thousands, if not millions, of genetic variants," he concluded.