Position Statement: Genetic Testing

Mar 4

Position statement on Genetic Testing

Nancy Laguette1
Prof Malcolm Collins
Prof Alison September1
Dr Mike Poshtumus1,2
1 The Division of Exercise Science and Sports Medicine, Department of Human Biology, The University of Cape Town Medicine.
2 The SSISA Academy


A number of companies claim to be able to predict risk of exercise-related injuries or illness, performance and talent identification in the sports arena using commercially available direct-to-consumer and mail-order genetic testing locally and abroad. 

We explore some of the complex ethical and practical concerns surrounding this specific topic, and present some recommendations. 

Background

More than 200 gene variants have been identified as potential contributors towards sport performance measures, athletic status and risk of exercise-related injuries. However, in this evolving field of research, and with some exceptions, there is a lack of replication of findings in larger independent population studies in addition to few functional studies to support and strengthen the genetic association studies. 

Moreover, few studies focus on South African populations, many of which display a unique and rich genetic diversity that differs from current consensus available online. Genetic variants unique to indigenous South African populations have not yet been identified, described or annotated on databases pertaining to the human genome. 

In addition, several environmental (external to the individual) and intrinsic factors (inherent to the individual) significantly contribute and interact to produce complex traits or conditions, and are not yet well understood by scientists and medical practitioners. Complex traits or conditions linked to sports performance, athletic status and risk of exercise-related injuries are multifactorial in nature. 

Therefore, dissecting the exact influence of a genetic component, or a few selected gene variants, in isolation is challenging.

Ethical and practical concerns 

Fundamentally, an individual’s genome remains unchanged throughout his or her lifespan with very few exceptions. This distinguishes genetic testing from non-genetic tests which often require the consumer to be of a certain age for the test results to be relevant, for example with performance tests. However, this aspect of genetic testing also poses ethical questions. Indeed, it could lead to misuse towards minors and embryos, erroneously marketed to predict sports performance, talent or sports-related illness.

Importantly, commercially available direct-to-consumer and mail-order tests in South Africa and abroad are poor predictors of risk of exercise-related injuries, talent identification and sports performance. The majority of the genetic tests available in this context lack the adequate depth, strength and reliability to support claims made by these companies. 

As mentioned before, the data known to scientists and available on the databases are limited by our current technology, knowledge and ability to decipher the meaning of variations within the genetic code. Moreover, the level of scientific evidence for many of these studies is relatively weak making the validity of the genetic tests questionable. Therefore, the information produced may not be valuable to the consumer in its current state and the cost-to-benefit ratio is heavily skewed. 

Results from a genetic test may be presented or interpreted inaccurately and out of context. For example, some genetic variations deemed to correlate with a protective or beneficial effect in one population study may associate in a divergent manner in another. 

A “one-size-fit-all” approach to direct-to-consumer genetic testing is inappropriate because of the diversity present across populations, individual profiles and presence of other factors which play a significant role in the modulation of these complex sports-related traits and/or conditions. Further in-depth evidence-based research is required in this field to support their claims. Indispensably, the presence of a genetic counsellor is needed to adequately present and interpret the data produced for the consumer. 

Beyond this, primary or incidental findings from a genetic test can also have a bearing on family members and partners. A personalised and cautious approach facilitated by the presence of a genetic counsellor and/or well-informed medical practitioner is essential to properly address this.

Confidentiality and secure storage of the data generated from the genetic test using the DNA and information provided by the consumer may not be guaranteed by the company supplying them. These are questions that need to be addressed to prevent future violations. 

Disclosure of genetic and other personal data should also be carefully considered when choosing to purchase such a test to prevent abuses such as discrimination towards consumers by third-parties such as coaches and insurers. 

Recommendations

In the context of sports performance and sports-related conditions, drawing conclusions from genetic tests that do not take into consideration the environment and other variables inherent to the individual is poorly predictive, unethical and should be cautiously interpreted. 

Several recommendations are therefore presented to mitigate some of the ethical and practical considerations related to genetic testing.

It is wiser to wait for a consensus generated by a reliable scientific body on genetic testing claims. Predictors of injury built on models that incorporate a number of clinically relevant risk factors will be built in the future to complement services with multidisciplinary approaches and in line with the concept of personalised medicine. 

In addition, if genetic testing is requested it must be done by informed, mature individuals, with no influence or interference by third parties such as an employer.