Being a carrier of the sickle cell trait, although generally not a serious problem, can pose significant risks for athletes, particularly those in intense training regimens

Question

The death of Florida State University linebacker Devaughn Darling, a carrier of the sickle cell trait, in a spring conditioning drill refocused attention on sickle cell abnormalities, including both sickle cell disease and sickle cell trait (carriers). High altitude, aggressive exercise, and high temperatures can all lead to acute rhabdomyolysis in individuals with sickle cell trait. Why do you think an individual who is a carrier of the sickle cell trait may be more likely to experience the symptoms of SCD during rigorous exercise?

Answer 1

Individuals who are carriers might never experience any symptoms of SCD, because they have enough normal RBCs to carry oxygen required for normal activities. However, if they are subjected to extreme conditions, they may have adverse reactions because they still have some sickle-shaped cells in their bloodstream. The hemoglobin contained in red blood cells of people with SCD is less stable than wild-type (normal) hemoglobin when oxygen concentration is low (due to high altitudes, high temperatures, or intense exercise). This instability can cause hemoglobin to collapse into linear, crystal-like molecules at low oxygen levels. Due to its high concentration in red blood cells, the collapse of hemoglobin into linear structures deforms red blood cells into the sickle shapes first seen by Ernest Irons. These sickle cells can clog the bloodstream, leading to intense cramping and pain often confused with heat or exercise-related exhaustion. However, it is clearly a more dangerous and potentially fatal problem.