A person inherits genes that produce hemoglobin from his/her parents. It is important to identify people with hemoglobin trait so they will be aware of their risk of having children with sickle cell disease. If one parent has sickle cell trait and the other parent has normal hemoglobin, there is a 50 percent chance with each pregnancy that the child will be born with sickle cell trait. If both parents have sickle cell trait or another hemoglobin trait, there is a 25 percent chance with each pregnancy that the child will have sickle cell disease or another hemoglobin disease.
People with sickle cell trait usually do not have any disease symptoms. However, it is possible for a person with sickle cell trait to have complications of the disease under extreme conditions, such as: