Speed Gene - ACTN3

What does it take to become an Olympic champion? Hard work and perseverance are no doubt part of the equation, but DNA may play a role too.

Scientists have discovered a variation in a gene that seems to affect whether a person will make it to the top of their game, at least in sports like sprinting and weightlifting that require quick bursts of powerful force. The gene is called ACTN3, but its role in athletic performance has led some to dub it the "gene for speed."

The ACTN3 gene encodes instructions for making a specific muscle protein. Researchers have found that some people have a non-working version of the gene that prevents it from making the muscle protein. More than a billion people worldwide have two copies of this variation in their DNA, causing their muscle cells to completely lack the protein.

Lacking the ACTN3 protein does not seem to have any harmful health effects, but there does seem to be an effect on sports performance. Several studies have found that Olympic-level power athletes always have at least one working copy of the ACTN3 gene. After studying hundreds of athletes, scientists came to the conclusion that it is probably impossible for someone who lacks the ACTN3 protein to reach the top levels of performance in power sports.

They were soon proven wrong. While looking for other genes that might determine athletic ability, a Spanish scientist hit upon an exception to the rule: a champion long jumper who has two non-working copies of ACTN3.

The long jumper has a history of great achievement. He competed at the international level at the age of 16, and went on to compete in several European and World championships. He has also participated in two Olympic games.

The fact that this long jumper is the first and so far only Olympic power athlete to be found who lacks the "gene for speed" is evidence for how important this gene is in determining this type of athletic ability. But his success is a testament to the fact that genes are not destiny.