I was reading an interesting blog post by Erin Mirabella (USA Olympic athlete in 2000, 2004 & children’s sports story author) about whether DNA testing can determine a child’s athletic potential.  As I work in an organization that assists athletes elevate their potential, I want to share my thoughts.

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Humans have 23 pairs of chromosomes that contain DNA.  DNA which makes up the chromosomes is the “blueprint” containing the genetic “instructions”.  These instructions are sent to RNA which, in turn, sends instructions to manufacture thousands of different kinds of proteins. The proteins are the building blocks of tissues and organs serving all biochemical, physiological and psychological processes.

In answering the big question: Do Genes Dictate Athletic Performance? There are two issues that every coach parent and athlete should understand.

1)       Human Performance is  Based on More than the Genotype.  Genes must interact with the environment to produce the qualities essential for athletic success.  Whereas genes are important, an appropriate environment is necessary for the genetic potential to be realized for successful athletic performance consisting of many phenotypes (e.g. stamina, speed, agility, etc.).

2)  More than One Gene is Involved in Performance. Humans have numerous genes that influence variation in traits like weight, eye color, height, etc.  Differences in even something as simple as eye color are controlled by multiple genes (the catalog of human inheritance lists 85 genes related to eye pigmentation).  If the differences in eye color are caused by so many genes, how many do you think help determine an athletic ability such as endurance?  In fact, begin thinking of the factors that contribute to endurance and you'll see how complex it is (e.g. motivation, concentration, stubbornness/willpower, stress management, persistence to goals, acceptance of personal responsibility).  Those are just the mental qualities. If you factor in the physical (bone density, anthropometrics, biomechanical stride, etc), you'll see the difficulty in relating performance to the genotype, since it likely depends on many genes, each contributing a small fraction to individual differences.

Therefore, I’m concerned when I hear discussions that DNA testing will determine a child's athletic potential.  That is not true--at least, not today and not in the foreseeable future.  There are two main reasons for this: a) there are far too many factors at play that determine that, and b) our science is simply not advanced enough--the world's best science is still searching for genes measurably contributing to variation in the risk for diseases like cancer and schizophrenia, despite their severity and considerable funds invested in research.

The way I think about the role of genetics is akin to running a race.  Genes determine your 'starting line' and your speed limits. You will not get very far, let alone to those limits, without running, and nobody will tell you what they are. The race conditions impact your performance, and how you 'finish' is ultimately up to you.  Good luck in your own "race"!