Sickle cell anemia is a recessive hereditary disease that causes the red blood cells to become sickle-shaped instead of round. Hemoglobin, the iron-rich protein inside the red blood cells that is responsible for carrying oxygen through the body, is defective. This incurable disease causes a range of chronic symptoms. As explained by the Journal of Occupational Medicine, sickle cell anemia affects all body systems and can cause debilitating damage to organs and muscles.
Causes
A mutated gene causes the body to produce deformed hemoglobin. This results in brittle, deformed red blood cells. People with the disease have inherited the defective gene from both parents. When only one gene is inherited, the individual is a carrier and can pass it on but will not have symptoms, except in rare instances.
Effects
The National Heart, Lung and Blood Institute explains that normal red blood cells live for 120 days, while sickled cells are brittle and fragile and live for only 20 days or so. Bone marrow cannot produce new red blood cells to compensate for the deficiency, and this causes a low red blood-cell count and decreased iron levels, leading to anemia. Sickled red blood cells also hinder normal blood flow, because they clump together and stick to the walls of blood vessels and organs. This can cause blood clots and blood-vessel narrowing.
Symptoms
Symptoms of sickle cell anemia include chronic fatigue, weakness and fast heart rate, according to the University of Maryland Medical Center. Blood clots can develop in the blood vessels, lungs and spleen, leading to infections, organ damage, heart disease and stroke. Other symptoms include chronic or recurring pain, chest infections, skin ulcers, swollen hands and feet and gangrene. Sickle cell anemia can also slow healing.
Delayed Growth and Development
Untreated sickle cell anemia can cause slow development and delayed growth in children. The low levels of red blood cells hinder the delivery of oxygen and nutrients to organs, tissues and cells. This can result in low weight, slower growth and delayed puberty in children.
Affect on Malaria
According to the journal Proceedings of the National Academy of Sciences, sickle cell anemia developed from a genetic mutation thousands of years ago that was made more prevalent by malaria. Malaria epidemics in areas prone to sickle cell anemia caused many deaths. But people who had sickle cell anemia or who carried the trait for it survived malaria. As a result, there is an unusually high number of people with sickle cell anemia in India, sub-Saharan Africa, Spain and the Mediterranean. The journal said the sickled red blood cells could have killed the malaria parasite before it could do any harm.
References
- Sickle Cell Society: Sickle Cell
- Journal of Occupational Medicine: What are the implications of sickle cell anaemia?
- National Heart Lung and Blood Institute: What is Sickle Cell Anemia?
- University of Maryland Medical Center: Sickle Cell Disease
- Proceedings of the National Academy of Sciences: Erythrocytic mechanism of sickle cell resistance to malaria
