Individuals who are heterozygous for sickle cell have what condition?

Individuals who are heterozygous for sickle cell have sickle cell trait. This means that they carry one normal hemoglobin gene and one abnormal hemoglobin gene associated with sickle cell disease. Since they possess one normal gene, these individuals typically do not exhibit the severe symptoms associated with sickle cell disease, which occurs in individuals who are homozygous for the sickle cell gene (having two copies of the abnormal gene).

Sickle cell trait usually does not cause medical problems, and most individuals with this condition go through life without knowing they have it unless they have genetic testing. Individuals with sickle cell trait can, however, pass the abnormal gene to their offspring, potentially leading to sickle cell disease if their partner also carries the gene.

Thus, being heterozygous for sickle cell means that the correct characterization of their condition is sickle cell trait, as opposed to the other options which either refer to the more severe condition of sickle cell disease, normal red blood cells, or a different hemoglobinopathy entirely in the case of thalassemia.