Final answer:
Sickle cell anemia is caused by a point mutation that substitutes valine for glutamic acid in the beta-globin chain of hemoglobin, leading to deformed, sickle-shaped red blood cells and health complications, predominantly among individuals of African ancestry.
Step-by-step explanation:
The disease caused by the substitution of valine for glutamic acid as a result of a point mutation is known as sickle cell anemia. This genetic disorder is characterized by a deformed shape of red blood cells, resembling a sickle, which leads to numerous health complications. Sickle cell anemia is prevalent among people of African descent due to a protective evolutionary advantage against malaria, despite its harmful effects.
The mutation occurs in the hemoglobin gene, specifically in the beta-globin subunit of hemoglobin. Normal hemoglobin contains glutamic acid at the seventh position, but in sickle cell anemia, valine is found at this position instead. As a consequence, the hemoglobin molecules aggregate and cause the red blood cells to become rigid and sickle-shaped, which can obstruct blood flow and reduce oxygen delivery to the body's tissues.
This single amino acid change out of the approximately 600 in the hemoglobin protein has a profound impact on the protein's function and the individual's health. Beyond the physical symptoms, individuals with sickle cell anemia may experience a reduced life expectancy and an increased need for medical care.