Ovalocytes, sometimes known as elliptocytes, are elongated or misshapen red blood cells that can be hereditary or the result of an acquired disorder. They are commonly seen in cases of iron-deficiency anemia and thalassemia. Ovalocytes sometimes occur in newborn infants.
People who inherit a tendency toward forming ovalocytes are said to have a condition known as hereditary elliptocytosis. As many as nine out of 10 people with this condition are mostly or totally asymptomatic, which creates difficulty in estimating the condition's prevalence in the general population. Certain subtypes of the condition confer resistance to malaria, resulting in a higher prevalence among populations in areas where the disease is endemic.