Definition of Sickle cell trait

Sickle cell trait: The condition in which a person has only one copy of the gene for sickle cell (and is called a sickle heterozygote) but does not have sickle cell disease (which requires two copies of the sickle cell gene). If two people with sickle cell trait mate and have children together, each of their children has a 25 percent chance of having sickle cell disease.