Discrimination between iron deficiency and heterozygous beta-thalassemia in children.

The authors studied 119 children with microcytic anemia who were selected by lack of response to a month's treatment with oral iron. Family studies and retesting after further treatment with iron were done in all cases to ensure accurate diagnosis. Seventy-five cases of beta-thalassemia minor (BTM) and 40 cases of iron deficiency were identified. In all 75 cases of BTM, at least one parent had a mean cell volume (MCV) less than 79 microns. In 35 of 40 children with iron deficiency, the MCV of both parents was normal. In contrast, Hb A2 was normal in 15% (11 of 75) of children with BTM, until they received additional treatment with oral iron. The authors conclude that in children with microcytic anemia unresponsive to a month's treatment with oral iron, the MCV of the parents is superior to Hb A2 in discriminating between iron deficiency and heterozygous beta-thalassemia. Repeated testing after additional treatment with oral iron may be needed to ensure accurate diagnosis.