Sickle cell anemia is a genetic disorder that results in the mutation of a component (β chain) of hemoglobin, an oxygen-carrying protein that can be found in red blood cells (RBCs). It is an autosomal recessive condition which means it occurs when the individual inherits one abnormal copy of the hemoglobin gene from each parent (resulting in a total of two copies of abnormal genes). This gene can be found on chromosome 11. In “stressful” conditions for the RBCs, the mutated hemoglobin (HbS) polymerizes and aggregates resulting in sickle-shaped RBCs (i.e. the shape of a reaping hook). This causes the red blood cell to continuously sickle and de-sickle, resulting in damage to its outer membrane. Thus, organs like the spleen (part of the reticuloendothelial system) remove these damaged RBCs from the circulation. However, RBCs can also dehydrate and rupture inside blood vessels (intravascular hemolysis) or produce occlusion of blood vessels and subsequent infarction of tissues (obstruction of blood supply and death of the tissue).
Symptoms of sickle cell anemia usually start around 5 to 6 months of age. An episode of sickle cell attack known as sickle cell crisis can be triggered by stress, dehydration, temperature changes, and high altitude. An individual with only one abnormal copy of the gene does not usually have symptoms and is said to have the sickle cell trait, otherwise known as carriers. The diagnosis can be made by screening for the mutated hemoglobin (HbS). Screening for this disease at birth is mandatory in many countries.
Management of the disorder includes the prevention of infection through vaccination, the use of pain medication for crisis, high fluid intake, and antibiotics. As of 2015, it has been estimated that 4.4 million individuals have sickle cell disease with an additional 43 million carriers. Approximately 80 percent of cases occur in sub-Saharan Africa. It is also frequently found in regions of the Arabian Peninsula, parts of India, and in people of African ethnicity in other parts of the world. This is likely due to the protective role of the disease against malaria caused by plasmodium falciparum.
Symptom #1: Pain
In sickle cell crises, periodic episodes of pain can occur. The pain occurs when the sickle-shaped red blood cells cause a blockage in the flow of blood through the tiny blood vessels to the joints, chest, abdomen, and more. Pain can also be experienced in the extremities, related to long bones. Varying in intensity, pain that occurs during sickle cell crisis can last from a few hours to a several days.
While some patients experience only a few pain episodes per year, others can suffer a lot more. Severe cases of sickle cell pain crisis may require hospital admission.