Hemoglobin C is a hemoglobinopathy, caused by an inherited abnormality of the beta globin gene. This disorder is inherited as an autosomal recessive trait. Hemoglobin C produces a mild type of anemia that occurs because the red blood cells containing abnormal hemoglobin are broken down prematurely.

Normal hemoglobin, known as hemoglobin A, is also present. The spleen may be enlarged, and there may be jaundice, a yellow color of the skin. Gallstones may develop and require treatment in adulthood.

The disease occurs predominantly in the black race. A family history of hemoglobin C is a risk factor. In combination with sickle hemoglobin, it results in Hemoglobin SC disease, which is characterized by hemolysis and painful crises. It is usually milder than sickle cell disease.