Sickle Cell Trait

Excerpt

Sickle cell disease was first described by James B Herrick in 1910. It was almost 4 decades later that Linus Pauling and his colleagues concluded that sickle cell disease was caused by a genetic disorder. It is one of the well-known molecular disorders. It is called molecular because it is caused by a single protein mutation. Sickle cell causes lifetime debilitation from chronic anemia, organ damage leading to poor quality of life, and early mortality. It is a major public health issue. Since the Sickle Cell Anemia Act was established in 1972, there has been more screening for sickle cell trait and disease. For instance, each state in the United States now offers newborn screening prior to discharge from the hospital.

There are different forms of sickle cell disease. They include Hb SS, Hb SC, Hb S beta-thalassemia, etc. All of these hemoglobin types cause a vaso-occlusive crisis. HbSS is the most common and severe type. HB SC occurs because patients inherit Hb S from one parent and Hb C from the other. Hb C is caused by a switch from glutamic acid to lysine. Hb S beta-thalassemia is very rare. It occurs when an individual inherits beta-thalassemia hemoglobin from one parent and HbS from the other parent. Vaso-occlusive crisis does not occur just because of sickling hemoglobin. It occurs because of multiple events, including deformed red blood cells, increased red blood cell fragility, and increased cation permeability and stickiness.

Sickle cell trait is benign because patients do not get vaso-occlusive crisis; they have a better quality of life and mortality is the same as the rest of the general population. Due to the benign nature of sickle cell trait, it generally does not have any clinical implications. However, there have been reports of adverse conditions that occur due to the patient's trait status. Therefore, sickle cell trait may not be completely benign and these patients should be managed aggressively whenever they develop some of these complications. This article discusses sickle cell trait etiology, epidemiology, histopathology, complications, and why more attention should be given to this condition.