beta-Thalassemia arising as a new mutation in an American child.

A 6-year-old child of northern European ancestry was found to have microcytic, hypochromic anemia with an elevated level of hemoglobin A2 and an unbalanced pattern of globin chain synthesis characteristic of beta-thalassemia trait. Hematologic and globin synthesis studies of both parents yielded entirely normal results. Identification of the mother and father as the biological parents was established with a high order of reliability by determination of erythrocyte, serum, and HLA genetic markers. These findings suggest that the picture of beta-thalassemia observed in this child represents a new mutation.