SICKLE CELL TRAIT
What is Sickle Cell Trait? From SCDAA
Sickle cell trait or the carrier state for sickle cell disease occurs in high frequency among people of African-American and/or Hispanic descent, but it can also occur in people of all ethnicities. For nearly three decades, screening for sickle cell disease and related hemoglobinopathies has been part of state-mandated universal newborn screening programs in the US. When properly conducted, testing for hemoglobinopathies also detects the carrier state for sickle cell disease and other hemoglobinopathies. These results have lifelong validity and for most people testing does not need to be repeated.
The sickle cell carrier state is associated with normal hematological values and normal life span. Knowledge of carrier status is important for reproductive planning since carriers can have children with sickle cell disease. Although uncommon, persons who are carriers for sickle cell may develop specific rare symptoms that may be related to sickle cell trait. These symptoms include hematuria, mildly reduced ability to concentrate urine, and a tendency to develop glaucoma secondary to hyphema after eye injuries. Knowledge of medical problems possibly associated with sickle cell trait and their appropriate management is an expectation of good clinical practice.
Persons with sickle cell trait have been shown to be more vulnerable than those without trait to heat stroke and muscle breakdown (rhabdomyolysis) when subjected to strenuous forced exercise in military training under unfavorable environmental conditions. Follow up studies demonstrated that the incidence of this problem can be reduced in all recruits by avoiding dehydration and overheating during training. Although similar studies have not been conducted in athletes, and exercise-induced rhabdomyolysis occurs in persons without sickle cell trait, concern has been raised as to the vulnerability of athletes with sickle cell trait to rhabdomyolysis during strenuous conditioning regimens. Deaths of healthy young athletes during conditioning are extremely rare, and are associated with sickle cell trait in less than half of the cases. Moreover, in many cases, such deaths are attributed to sickle cell trait because of the presence of sickled cells in tissues at autopsy, even though the occurrence of post-mortem sickling is well documented in sickle cell trait and expected with death from any cause.
Screening athletes for sickle cell trait and subjecting carriers to alternative training regimens, as recommended by the National Collegiate Athletic Association (NCAA) and National Athletes Trainer’s Association (NATA), has not been demonstrated to reduce the incidence of training-related deaths. Nevertheless this approach carries great risk of stigmatization and discrimination against athletes with sickle cell trait. The NCAA mandate for sickle trait screening does not provide adequate assurance of the privacy of genetic information nor protection from the discriminatory use of such information.
The Sickle Cell Disease Association of America (SCDAA) supports the implementation of universal, safe training guidelines for all athletes, and to rigorously educate and 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. Given the lack of scientific evidence that substantiates 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 to reduce heat related illness or death in athletes who are carriers. The commonsense precautions recommended by NATA — building up exercise intensity gradually, responding to athletes reporting symptoms of physical distress, and avoiding overheating and dehydration – if applied universally, would make athletic training safer for all and would obviate the need to identify carriers of the sickle cell gene in the athletic setting. Therefore, the need to identify athletes who are carriers of the sickle cell allele in the athletic setting is unwarranted.
The SCDAA makes the following recommendations for those athletic programs that choose to follow those of the NCAA Recommendations:
- Universal precautions to reduce dehydration and the chances of heat or exercise related illness, as demonstrated in the training of Army recruits, should be implemented for all athletes in training and competition. By implementing universal precautions, athletic programs could allow athletes to maintain the privacy of their sickle trait status. 1a. Athletic personnel should be trained in resuscitation techniques, appropriate equipment should be maintained at practice fields, and ready access to emergency medical assistance assured. Team physicians should be encouraged to conduct training exercises with athletic staff to insure competent management of emergencies.
- Genetic information, like all personal medical history, should be protected in accordance with the Health Insurance Portability and Accountability Act (HIPAA) and handled by personnel who are duly authorized to have access to such personal information.
- Screening for genetic conditions, outside of state-mandated universal newborn screening, should be voluntary, and informed consent (and assent of minors of appropriate age) should be obtained.
- In accordance with the Genetic Information Nondiscrimination Act (GINA), screening for sickle cell disease and related hemoglobinopathies must not lead to stigmatization or discrimination of those tested based on the testing or its results. In the context of athletic screening for sickle cell trait, the athletic associations bear responsibility for demonstrating that its recommendations do not have discriminatory effects on athletes.
- Screening for sickle cell disease and related hemoglobinopathies, like all genetic testing, should be preceded by counseling to explain the benefits and risks of testing, and followed by genetic counseling and health education that explain the results and their implications.
- Screening for sickle cell disease and related hemoglobinopathies should be not be performed using solubility or sickling tests that merely suggest the presence of hemoglobin S. These non-specific tests cannot distinguish heterozygous sickling disorders from sickle cell disease, and fail to identify other common hemoglobin variants and provide misleading information with respect to genetic counseling. Laboratory methods that identify specific hemoglobins or mutations are preferable.
- SCDAA will increase their efforts to work with professional and community-based health organizations, public health officials, and educational institutions to provide educational programs regarding the risks and management of all causes of injury and death in athletic activities.
- SCDAA will work with public health experts to conduct research to determine the epidemiology of the risk of sudden death or exercise related illness in people with sickle cell trait and, if a significant association is established, further research into the causes and management should be conducted.
- Athletic organizations at school, collegiate, and professional levels should be encouraged to collect and maintain records on athletes and athletic conditions that may be useful in understanding unexpected death and injury in athletics.
- SCDAA, the Health Resources and Services Administration, the Centers for Disease Control and Prevention, the National Collegiate Athletic Association, the National Institutes of Health/National Heart, Lung and Blood Institute and the National Athletic Trainer’s Association should collaborate to collect research related epidemiologic and clinical data on athletes who are being screened for sickle cell trait with the goal to correlate carrier status and sports related heat injury.
The Medical and Research Advisory Committee (MARAC) of the Sickle Cell Disease Association of America, Inc. in collaboration Key Opinion Leaders and Federal partners developed carrier screening recommendations from proceeding from meetings convened on December 17, 2009 and February 18, 2010.
National Athletic Trainer’s Association (NATA)
Precautions and Treatment
No sickle-trait athlete is ever disqualified, because simple precautions seem to suffice. For the athlete with sickle cell trait, the following guidelines should be adhered to:
- Build up slowly in training with paced progressions, allowing longer periods of rest and recovery between repetitions.
- Encourage participation in preseason strength and conditioning programs to enhance the preparedness of athletes for performance testing which should be sports-specific. Athletes with sickle cell trait should be excluded from participation in performance tests such as mile runs, serial sprints, etc., as several deaths have occurred from participation in this setting.
- Cessation of activity with onset of symptoms [muscle ‘cramping’, pain, swelling, weakness, tenderness; inability to “catch breath”, fatigue].
- If sickle-trait athletes can set their own pace, they seem to do fine.
- All athletes should participate in a year-round, periodized strength and conditioning program that is consistent with individual needs, goals, abilities and sport-specific demands. Athletes with sickle cell trait who perform repetitive high-speed sprints and/or interval training that induces high levels of lactic acid should be allowed extended recovery between repetitions since this type of conditioning poses special risk to these athletes.
- Ambient heat stress, dehydration, asthma, illness, and altitude predispose the athlete with sickle trait to an onset of crisis in physical exertion.
- Adjust work/rest cycles for environmental heat stress
- Emphasize hydration
- Control asthma
- No workout if an athlete with sickle trait is ill
- Watch closely the athlete with sickle cell trait who is new to altitude. Modify training and have supplemental oxygen available for competitions.
- Educate to create an environment that encourages athletes with sickle cell trait to report any symptoms immediately; any signs or symptoms such as fatigue, difficulty breathing, leg or low back pain, or leg or low back cramping in an athlete with sickle cell trait should be assumed to be sickling.
Source: NATA Consensus Development Document
*The NATA’s recommendations posted on the NATA website and are provided for your information only. Providing this information to you does not translate to an endorsement of these recommendations by the SCDAA nor Cayenne Wellness Center.
From the National Academies of Sciences • Engineering • Medicine, a consensus study report on Addressing Sickle Cell Disease: A Strategic Plan and Blueprint for Action, we invite you to read the section on Sickle Cell Trait (pgs 162 – 162). Click here.