“OK, officer, I admit it. I failed to indicate when I pulled out and didn’t notice the zebra crossing. Oh, and sorry for cutting you up. But go easy on me. I haven’t slept in days, I’m late for an appointment, and I have a Val66Met. Yep, that’s right. I have the bad-driving gene.”
Ridiculous though it seems, scientists in California have found that genes might influence driving ability. In a small study of students, those with one particular variant of a gene performed worse on a driving simulator than those with other variants. The researchers have since suggested a follow-up study: swabbing drivers who cause road accidents to see if the laboratory results depict a wider genetic truth or if the idea of congenitally poor drivers is an intellectual cul-de-sac.
The experiment, by Stephanie McHughen and colleagues at the University of California at Irvine, focused on a gene that produces a protein called brain-derived neurotrophic factor (BDNF). You can think of BDNF as Red Bull for the brain: when we care carrying out a task, the brain secretes a shot of BDNF to improve our ability to think and learn (by keeping brain cells talking to each other). It is vital to neuroplasticity — the brain’s ability to learn on the hoof.
How much BDNF we produce depends on which variant of the gene we have: those with the Val66Met version secrete less, those with other variants (there are several) secrete more. About a third of the population has the Val66Met variant.
The academics wanted to see if this variation produced a measurable effect on motor activity. And what better way to test it than using motors? Not real ones, but a simulator in the laboratory. And so 29 students were given the chance to be armchair Lewis Hamiltons, doing 15 laps on a twisting course. Then they came back and did the task four days later.
Advertisement
If you already know you have the Val66Met variant, look away now. The seven students who had the variant were 20 per cent worse than the “unafflicted” 22 students. While all the students improved with each lap, those with the Val66Met variant improved less than others. In the rerun four days later, the owners of this villainous variant were again at a disadvantage and seemed to remember fewer of the hairpin bends.
Even the scientists were shocked by the clarity of the findings, because the study was relatively small (only 29 subjects in total) and driving is such a complex activity. As Dr Steven Cramer, a co-author, puts it: “These people make more errors from the get-go, and they forget more of what they learnt after time away.” The study appears in the journal Cerebral Cortex. So dramatic are the results, Cramer says, that it would be worth investigating the genetics of people involved in car crashes.
Being a genetic menace on the roads might have an upside, however. While people with the Val66Met variant in the BDNF gene might not have terribly nubile brains. they seem to be less severely affected by such diseases as Parkinson’s, Huntingdon’s and multiple sclerosis. The gene variant doesn’t make them particularly less likely to contract these diseases — but it does seem to protect cognitive ability when they hit. Cramer infers that the payoff of having a less flexible brain is a more stable brain, less prone to the knocks and insults of neurodegenerative complaints. This trade-off possibly explains why Val66Met is still in the gene pool.
What with the current fashion for delving into one’s genome, it was only a matter of time before a gene-testing company hooked itself up to the story. Last week, 23andMe publicised the study on its blog and told customers that they could check their BNDF gene status, to see if they possess the offending variant (which previous studies have suggested is also correlated with competence at computer games). It might also make rather illuminating reading for their car insurers.