Sickle cell disorders

Sickle cell disorders are inherited. That means they are passed from parent to child. Children with sickle cell disease have two defective hemoglobin S genes, one from each parent. Various forms of sickle cell disorders occur when a person inherits one hemoglobin S gene (sickle cell gene) from one parent and one other type of defective hemoglobin gene from the other parent.

Normally, a person inherits two genes that tell the body to produce normal hemoglobin A. One gene comes from each parent. People who inherit one defective hemoglobin S gene and one normal hemoglobin A gene have sickle cell trait. These people rarely have symptoms of sickle cell disease. Their bodies don't make sickled blood cells. But, as carriers, they can pass the defective hemoglobin S gene to their children.