[Thalassemia major manifested by megaloblastic anemia caused by folate deficiency].

In a 11 month-old child, a deep anemia with reticulocytopenia and megaloblastosis on bone marrow aspiration revealed a thalassemia major. The low folate intake and the increased needs probably account for initial findings. Folic acid deficiency has already been described in patients with dyserythropoiesis or chronic hemolysis. Daily folic acid treatment is necessary in these patients.