Trait, sickle cell: A person who possess one copy of the gene for sickle cell anemia. This person carries the gene but does not have the disease (or any adverse effects). If two people with sickle cell trait have children together, each of their children has a one in four chance (25%) of having sickle cell disease.
A person with sickle cell trait is termed a sickle heterozygote. A person with sickle cell disease is a sickle cell homozygote. Sickle Cell Trait is particularly common in areas of the world in which malaria is endemic. This trait is protective against malaria explaining its evolutionary advantage and high prevalence