Feasibility of molecular diagnosis of alpha-thalassemia in the evaluation of microcytosis.

Microcytosis is a common hematological finding, usually related to iron deficiency or beta-thalassemia. When both of these conditions are excluded, alpha-thalassemia must be considered in the differential diagnosis. No simple biochemical test is able to diagnose the alpha-thalassemia trait. Using PCR amplification of the breakpoint in deletional forms, and amplification of the alpha 2 gene and restriction enzyme digestion in non-deletional forms, we identified the alpha-thalassemia carrier status in 42 out of 51 (82%) patients with microcytosis or slight microcytic anemia, unrelated to iron deficiency or beta-thalassemia. Our results underline the usefulness of molecular tests in clinical practice.