A recent commentary published in the Journal of the American Medical Association (JAMA) calls attention to the potential harms associated with testing children for genes associated with sports performance.
What differentiates the results reported in this study of genes associated with athletic performance from other association studies appears to be the lack of strong evidence supporting this association with athletic performance. This means that unlike certain genes that really have been associated with, say heart disease, at the level of a population, the jury is still out on the evidence for genes associated with athletic performance. So if we’re not sure at the population level, it means that this test is of no practical value for any individual (or as this article mentions – the hopeful parent of an indifferent child) who wishes to predict the future likelihood of being a professional athlete.
Since the entire human genome was sequenced and reported over a decade ago to great fanfare, the public has been waiting to see the practical benefits of applying this knowledge. So far, there has been little for them to see. A number of commercial enterprises have arisen that sequence an individual’s DNA and report on which versions of a number of genes the person has. These genes have been associated with risk of cancer, heart disease, diabetes, rarer genetic conditions, but all suffer from the fact that while the specific gene variants may be predictive at a population level, they so far offer little to the individual patient. In this context, one can now add genes associated with athletic performance.
According to the story, the testing kit costs about $170.
The story does not present any data from the research on this topic. It would have been helpful had it included some of the data from the JAMA commentary to illustrate the variability in the evidence. For example, smaller studies have found that between 31% and 73% of elite power/sprint athletes express the ACTN3 gene compared to a range of 26% to 45% in control groups. Again, finding the probability that the individual tested would be a professional athlete before and after testing would be ideal.
Throughout the story, the writer touches on the ethical and psychological implications of this test; however, it would have been useful had it mentioned other potential harms outlined by the authors of the commentary in JAMA. For example, specialization in a sport at a young age may lead to injury and/or burnout. In contrast, children who test negative for the gene may be discouraged and limit their participation in sports. This decrease of physical activity could lead to health issues in the future. In addition, there is the potential that the ACTN3 gene may later be associated with disease risk and these people will have not received the proper counseling.
In general, the piece covered a lot of gorund with this one quote: “This is recreational genetics with a real serious potential for harm,” Ross said. “People are going to think, `If my kid has this, I’m going to have to push real hard. If my kid doesn’t have it, I’m going to give up before I start,” she said. Instead, Ross said, parents should “let kids follow their dreams.”
While the story indicates that the evidence regarding the ACTN3 gene and athletic performance is still in its “infancy,” it could have provided more detail on where the evidence is lacking. For example, one of the major studies that found an association between the gene and athleticism included only white participants, suggesting that the results may not apply to the general population. As the JAMA commentary points out, the significance of this gene in people who are not elite or professional athletes is still unknown and the studies evaluating this gene are relatively small. In theory, one would like to see an estimate of the likelihood of a child becoming a professional athlete in the sampled population and then a revised likelihood after the test was performed and found to be either positive or negative.
The story did not engage in disease mongering. It points out that while 80% of the population has the ACTN3 allele, only a fraction are elite athletes, underscoring the fact that athletic ability is multifactorial.
A particular strong point of this story is that it provides multiple viewpoints, including:
Although the story does not go into any detail, it does mention that there are several genes associated with athletic performance, not just ACTN3.
But the real alternative is NOT to test.
The story makes it clear that this test is easy to obtain through mail-order.
According to the story, one U.S. company has been marketing this test since 2008.
This piece does not rely on a press release.