I read the article by Harris et al describing an association between sickle cell trait (SCT) and sudden death in athletes. The authors examined the 31-year United States Sudden Death in Athletes Registry to evaluate the effect of SCT. The prevalence of SCT in football players (7%) was similar to the prevalence in the black population in the United States (8%). This certainly speaks to a possible association between SCT and sudden death in this smaller cohort of football players. However, as a pediatric hematologist, I was struck by the finding that of the 23 athletes described in the study, 7 had undergone a solubility test alone to identify their sickle cell status. This is merely a qualitative test confirming the presence or absence of hemoglobin S. The test is inadequate to differentiate SCT from a clinically significant sickling hemoglobinopathy. As such, these 7 patients should be removed from the analysis.

This would leave 16 of the 2,462 athletes in the registry confirmed to have SCT (0.6%). There were 699 black athletes in the registry, 2.3% of whom had SCT. As noted by the authors, 8% of black Americans have SCT. It seems that athletes with SCT were actually underrepresented. The authors report that 4 of the 23 patients with SCT also had structural cardiac abnormalities discovered at autopsy. It would be interesting to know whether these patients truly had SCT and whether they were within the smaller football cohort. When considering specifically football players, only 12 of 271 athletes (4%) who died were confirmed to have SCT. This also means that 259 black football players without SCT died. Again, even within the smaller cohort of football players, athletes with SCT were underrepresented.

I applaud the authors’ work and, specifically, the description of the clinical profiles and scenarios of the SCT athletes. However, it is unclear how many of the other 2,439 athletes shared similar stories. I am most concerned about the authors’ statement that “7% of 271 African American football players in the registry died of SCT.” More research is needed before a definitive statement such as this can be made. This is dangerous language that could scare thousands of young men and women and potentially deter them from safely participating in sports. In fact, we encourage our patients with sickle cell disease to fully participate in life, including sports if they so chose. We do, however, recommend following a specific training and self-care regimen to which all athletes should adhere.

As was nicely stated by the authors, this has become a controversial topic, especially in light of the National Collegiate Athletic Association’s decision to require SCT testing for student athletes. The American Society of Hematology recommends the implementation of universal interventions to reduce exertion-related injuries and deaths, because this approach can be effective for all athletes, irrespective of their sickle cell status. Continued work is needed to elucidate the role of SCT in sudden death in competitive athletes. In the meantime, athletic training policies should be implemented to protect all student athletes.