Sickle Cell Trait

Sickle cell trait occurs when a person inherits a sickle cell gene from just one parent. It's not the same as sickle cell disease, in which a person inherits two sickle cell genes, one from each parent. People with sickle cell disease have just one kind of hemoglobin (hemoglobin S), which turns their normal, round red blood cells into abnormally curved (sickle) shapes. But people with sickle cell trait have both normal hemoglobin (hemoglobin A) and hemoglobin S, so they rarely have symptoms of sickle cell disease. But they are carriers and can pass the sickle cell gene to their children. Abstract source