Alexis Thompson, MD, MPH
A. Watson and Sarah Armour Endowed Chair for Blood Diseases and Cancer; Hematology Section Head, Division of Hematology/Oncology Transplantation; Children’s Memorial Hospital, Professor of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL
Sickle cell disease, an autosomal recessive disorder caused by the inheritance of two abnormal β-globin genes, is routinely diagnosed and managed by hematologists, but sickle cell trait has been the focus of recent heightened attention. Millions of Americans and hundreds of millions of people worldwide are carriers of the sickle cell mutation affecting one of their two β-globin genes. Individuals with sickle cell trait generally live normal, healthy lives; however, under extreme conditions, such as severe dehydration and high-intensity physical activity, complications including rhabdomyolysis, splenic infarction, and papillary necrosis can occur. The National Collegiate Athletic Association (NCAA) estimates that approximately 400,000 student athletes compete each year in sports under its sanction. During a five-year period from 2004 to 2008 in which athletes logged nearly 2 million participant-years, 273 deaths were reported by the NCAA with five of those deaths occurring in athletes with sickle cell trait. In April 2010, the NCAA adopted a policy requiring Division I institutions to perform testing for sickle cell trait on all incoming student athletes. This requirement followed a lawsuit that was filed after the death of a college football player during preseason training. Post-mortem investigation into the cause of death revealed that the player had sickle cell trait. The NCAA policy includes an opt-out provision for students who can provide results from a prior test and for those who are willing to sign a waiver exempting both their university and the NCAA from liability. Because ASH is devoted to the study and treatment of blood disorders, including sickle cell disease and sickle cell trait, the Society initiated a process to address the scientific, medical, and ethical issues raised by the NCAA’s policy.
In June 2011, ASH hosted a workshop aimed at determining whether, based on available evidence, individuals with sickle cell trait are at increased risk for exertion- or heat-related illness or sudden death. The workshop also sought to determine if there was evidence-based support for requiring adult screening for sickle cell trait as a prerequisite for participation in athletics. Physicians and researchers with expertise in sickle cell biology and treatment joined with representatives from the U.S. military and other federal agencies for an in-depth discussion of scientific data on the association between sickle cell trait and adverse health outcomes, including but not limited to exertion-related illnesses. In addition to an assessment of data published in scientific journals, panel members reviewed information on efforts by the military to mitigate heat-related risk, qualitative research on the impact of the NCAA mandate on athletes, and records of deliberations by other organizations on this topic.
As part of the discussion, the workshop participants reviewed and affirmed the Society’s support of screening of newborns for sickle cell disease. Newborn screening for sickle cell disease is currently performed in the United States in all 50 states as a public health imperative, because there is strong empirical evidence that early detection and intervention reduces morbidity and mortality in young children. While the Society supports newborn screening for sickle cell disease, there are no comparable well-controlled, prospective clinical studies that demonstrate a direct benefit for large-scale screening for adults. Voluntary screening beyond the newborn period paired with confidential counseling by knowledgeable providers can assist individuals in evaluating their own personal health status.
Published reports from the U.S. military in the 1980s identified an association of sickle cell trait and increased deaths during training. Subsequent work by the Army has focused on modification of their procedures related to the conduct of training, including heat acclimatization, monitoring rest/work cycles, and developing extensive protocols on the identification and treatment of suspected exertional heat-related illness (EHI). The Army discontinued screening for sickle cell trait in 1996, and their intervention measures have been fully implemented, which have resulted in a marked decline in deaths due to EHI in all recruits, including soldiers with sickle cell trait. Similar reductions in deaths have not been reported in other branches that have not adopted universal interventions.
ASH believes the current NCAA policy is not based on sufficiently strong scientific evidence and has the potential to cause inadvertent harm to the student athlete. The panel concluded that the NCAA policy for sickle cell trait screening of Division I athletes does not comply with best practices of testing and counseling of individuals for inherited conditions. The sickle solubility test lacks sufficient specificity and may give misleading results, as it cannot distinguish carrier status from diseases, which is particularly important in variant sickling syndromes such as HbSC disease. Safeguards for protecting genetic information are not apparent, putting the athlete at risk for stigmatization and discrimination. These issues extend beyond the playing field and persist long after the athlete’s four-year NCAA eligibility has expired.
Other organizations have raised similar concerns. In May 2011, the Medical and Research Advisory Committee (MARAC) of the Sickle Cell Disease Association of America (SCDAA) released recommendations in response to the NCAA ruling. MARAC concluded that given the lack of scientific evidence to substantiate a significant correlation between sickle cell trait in athletes and training-related sudden death, SCDAA does not support screening of athletes for sickle cell trait as a means of reducing heat-related illness or death. SCDAA supports the implementation of universal, safe training guidelines for all athletes and recommends rigorous education to improve the capacity of athletic coaches and trainers to recognize signs and symptoms of heat-related illness and to provide medical care to athletes who become ill or injured under their supervision.
The U.S. Department of Health and Human Services (HHS) Secretary’s Advisory Committee on Heritable Disorders in Newborns and Children developed a report in 2010 on screening of U.S. college athletes for sickle cell trait. While individuals should understand the medical and genetic consequences of sickle cell trait, the committee recommended that genetic testing should not be a prerequisite for participation in sports, unless deemed medically necessary, and that evaluation should include counseling, with safeguards in place to assure the privacy of genetic information. The committee also recommended that all athletes be given education on safe practices for the prevention of exercise- and heat-related illnesses. These recommendations were formally endorsed by HHS Secretary Kathleen Sebelius in June 2011.
Early this year, ASH contacted the NCAA to share its concerns and, on January 26, released its own policy statement on sickle cell trait and athletic participation that takes a different approach than the NCAA policy (see sidebar). A number of other organizations have announced their support of ASH’s position, including SCDAA, the American Society of Pediatric Hematology/Oncology, the American Public Health Association, the Association of Public Health Laboratories, and the American Society of Clinical Pathology.
The NCAA has expressed its willingness to discuss its policy with ASH and other stakeholders and explore these issues in an effort to better protect the health of athletes with sickle cell trait. As this article went to press, ASH was working to assemble a meeting with experts from the appropriate disciplines to review further the scientific data on the complex associations between sickle cell trait and health outcomes. Check the ASH website for the latest updates on this important public health initiative.
|ASH's Policy Statement on Screening for Sickle Cell Trait and Athletic Participation
- ASH does not support testing or disclosure of sickle cell trait status as a prerequisite for participation in athletic activities.
- ASH recommends the implementation of universal interventions to reduce exertion-related injuries and deaths, since this approach can be effective for all athletes irrespective of their sickle cell status.
- ASH believes that the NCAA Division I policy, as currently written and implemented, has the potential to harm the student athlete and the larger community of individuals with sickle cell trait.
- ASH strongly supports increased biomedical and population-based research on sickle cell trait as it relates to exertion-related illness, as well as other conditions.
Get more information about the policy statement.
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