SummaryThis paper describes clinical findings in subjects heterozygous for hemoglobin C and in compounds heterozygotes SC. Most of our patients were coming from lands hording the Guinea Gulf, on the inside of the loop made by the river Niger and from Haiti, which populated by African slaves coming mainly from the Golden Coast (actually Ghana). Heterozygous are Symptomatic and do not suffer from anemia. Age at diagnosis is higher than for SCA, although one of our cases was diagnosed at age one. Overwhelming infections or major anemia were not observed. Basal hemolysis remained moderate. HbF levels were not increased as they may be in sickle cell anemia. Splenomegaly was observed in 2/5 patients. Among severe complications we encountered, we must mention one case of foetal death, one tibial infarct, one case of pure red cell aplasia caused by parvovirus B19 infection, and one case of proliferative retinopathy.