Why do African Americans get sickle cell anemia more often?

People can only get sickle-cell disease if their ancestors came from regions in Africa where the inhabitants carry sickle-cell genes.

Sickle-cell disease is an inherited condition that originally occurred in African regions where malaria is present. A person who inherits a single sickle-cell gene has a tolerance for malaria and will have fewer symptoms if they become infected with malaria. Therefore, in those regions, sickle-cell genes were beneficial and became widespread.

Unfortunately, anyone who inherits two sickle-cell genes will have sickle-cell disease.