Clinical presentation of sickle cell-hemoglobin C disease.

Early symptoms were observed in a representative sample of 166 children with sickle cell-hemoglobin C disease diagnosed at birth. Symptoms were uncommon in the first year of life; in approximately 50% specific symptoms had developed by 5 years, but 22% remained without specific symptoms to 10 years. The age at presentation was significantly earlier in patients with low hemoglobin F levels, but was not influenced by heterozygous alpha-thalassemia-2. Painful crisis was the initial manifestation in 77% of the children; other symptoms included dactylitis (14%) and pneumococcal septicemia and acute splenic sequestration (4% each). The commonest nonspecific symptom was acute chest syndrome. The relatively mild early clinical course of sickle cell-hemoglobin C disease indicates that neonatal diagnosis does not have the same urgency as for homozygous sickle cell disease.