Hemoglobin C disease

Hemoglobin C disease (Hb C disease) is an inherited hemoglobin disorder caused by a specific point mutation in the beta-globin gene (HBB), resulting in the substitution of lysine for glutamic acid at position 6 of the beta-globin chain (Glu6Lys). This abnormal hemoglobin, known as hemoglobin C, tends to crystallize within red blood cells, reducing their flexibility and leading to their premature destruction (hemolysis). The disease primarily affects the hematologic system. Hemoglobin C disease is most prevalent among individuals of West African descent, particularly those from Ghana and Burkina Faso. Individuals who are homozygous for hemoglobin C (Hb CC) typically experience a mild to moderate chronic hemolytic anemia. Key clinical features include splenomegaly (enlarged spleen), mild jaundice, and occasional episodes of abdominal or joint pain. A hallmark finding on peripheral blood smear is the presence of target cells (codocytes) and intraerythrocytic hemoglobin C crystals. Most patients with Hb CC disease have a relatively benign clinical course and maintain a near-normal quality of life. Heterozygous carriers (Hb AC trait) are generally asymptomatic. Treatment for hemoglobin C disease is largely supportive. Most patients do not require regular transfusions or specific therapy. Folic acid supplementation may be recommended to support red blood cell production in the setting of chronic hemolysis. Patients should be monitored for complications such as gallstones (cholelithiasis) resulting from chronic hemolysis. Genetic counseling is recommended for affected individuals and carriers, particularly regarding the risk of compound heterozygous conditions such as hemoglobin SC disease, which can cause more significant clinical complications similar to sickle cell disease.

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