Sickle cell anaemia | Genetics | Biology | FuseSchool

Sickle cell anemia is an inherited disorder affecting red blood cells. Normally, red blood cells are round and flexible, carrying oxygen with hemoglobin. In sickle cell anemia, a mutation in the hemoglobin gene causes red blood cells to become inflexible and crescent-shaped, leading to blockages in blood vessels.

Blockages prevent oxygen and glucose from reaching cells, causing a 'sickle cell crisis' with severe pain. These crises can last minutes to weeks and lead to life-threatening complications, such as strokes if blockages occur in brain blood vessels.

To have sickle cell anemia, an individual must inherit two copies of the faulty recessive allele. People with one copy are carriers. If two carriers have children, there's a risk of having children with the disorder, children who are carriers, or unaffected children.

Approximately 4.4 million people worldwide have sickle cell anemia, with 43 million being carriers. It is most prevalent in Central Africa, India, the Middle East, and among people of African origin. These regions also have high rates of malaria.

Carrying the sickle cell allele offers protection against malaria. The malarial parasite, which spends part of its life cycle in red blood cells, causes the fragile red blood cells of carriers to burst prematurely, preventing the parasite's development and breaking its life cycle.