Have you read The Sports Gene? Maybe you are wondering if your child might be the next Lionel Messi? Or maybe you’re wondering why you were always picked last for kickball? Was it the genes? the practice? or a combination of the two?
We all know kids who seem to have been born with a baseball bat or tennis racquet in their hands. Tall kids, strong kids, fast kids and kids with great hand-eye-coordination. As far back as 1978, the German Tennis Federation had identified 9-year old Steffi Graf as a top recruit based upon her lung capacity, ability to sustain concentration, running speed and her competitive desire. Other kids discover late in life that they have a genetic gift. On a whim, Donald Thomas leaped for his first EVER high jump in 2006 and promptly won the World Championships in 2007. Chrissie Wellington (world tri-athelete champion) also accidentally discovered her genetic gift late in life (outpacing sherpas on her bicycle while vacationing in Nepal).
As described by David Epstein, the 1996 Olympic games in Atlanta, saw 7 women out of the 3,387 competitors carrying the Y-chromosome-linked SRY gene. 21-hydroxylase deficiency also causes the overproduction of testosterone and is over-represented among top female athletes. The GIANT research consortium has discovered hundreds of “sports genes”, such the rs9930506 SNP in the FTO gene, that contribute to body shape and size. Even more numerous are the complex genetics of height where each genetic variant adds a mere 2-6 millimeters toward NBA stardom. Elite sprinters are more likely to carry 2 functional variants of the fast-muscle-twitch ACTN3 gene. Lastly, an extended network of genes associated with muscle development can – when artificially overexpressed – induce muscle growth: insulin-like growth factor-I (IGF-I), growth hormone (GH), erythropoietin, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) and myostatin blockers, such as follistatin.
Sports genes. Few of us are born with them (I was luckily born with the non-obese TT genotype at rs9930506 in the FTO gene, but alas, this allele is associated with a lower response to exercise). Fewer still might be intent upon purchasing a genetic endowment via the taboo art of sports gene doping, especially if they carry the right UGT2B17, CYP17 and PDE7B genotypes. Most of us, however, would just like to maximize our paltry genetic endowments the old fashioned way.
Justin Durant of the Sports Science Institute of South Africa is quoted, “I’ve never seen a boy who was slow become fast” but how about late-blooming middle distance runner Jim Ryun whose practice regimen carried him from 21rst on his Wichita East track squad (in 10th grade) to an Olympian and 1-mile world record holder just a single year later? Epstein explores how each of us has an inherent genetic endowment for “trainability” ie. the extent to which our bodies and abilities respond to training. And yes, here too, molecular genetics researchers have identified more “sports genes” in a so-called training responsive transcriptome consisting of genes, including RUNX1, SOX9 and PAX3 whose expression is associated with exercise-dependent muscle growth and CREB1 whose expression is associated with improvements in heart rate and blood pressure.
Sports crazed parents should take note. Your child is probably totally average. Probably like self-described “totally average guy” Dan McLaughlin, who has slogged some 5,500+ hours into his personal experimental journey of “deliberate practice” hoping to land a spot on the PGA tournament by the time he reaches his 10,000th hour of practice. Will he make it? Or will he discover the oft-misconstrued “10,000 hour rule” is more like 4,000 for some and 40,000 hours for others. We wish Dan the best of luck on his quest, but also wish parents to use their children’s precious 10,000 hours for reading, writing, mathing and playing sports for fun rather than trying to attain an NCAA scholarship through mastery of a niche sport.
Will genetic counselors soon be found in pro sport locker rooms or at your local fantasy league draft party? Doubtful, but in 2005, according to Epstein, the Manly Sea Eagles of Australia’s National Rugby League became the first pro sports team to admit that it was genotyping players at ACTN3 and training them differently based on their genotypes.
I loved reading The Sports Gene! Have you ever noticed that NOBODY wants to read a blog or talk about genetics and medical illness, while EVERYBODY loves to talk about sports? Find me a graduate student who can understand (and stay awake while reading) medical GxE research and I will find 1,000 parents who are obsessed with finding the perfect sporting niche and coach for their child.
Whether it be medical treatment or athletic training, a good doctor/coach will seek to optimally match the patient/player’s genetic endowment with treatment/training. The Sports Gene by David Epstein is thus a wonderfully fun and timely playground for readers to explore the complexities of personal genomes and GxE interactions!