Ringed sideroblasts found in a girl heterozygous for the initiation codon (ATG-->AGG) beta0-thalassemia mutation.

The initiation codon (ATG-->AGG) mutation of the beta-globin gene is relatively rare, but has previously been found in Chinese and Korean families. We now report the case of a 5-year-old Korean girl who was heterozygous for this mutation, and who presented with mild anemia, increased stainable iron and ringed sideroblasts in her bone marrow. These observations underscored the importance of searching for possible beta-thalassemia (thal) mutations in patients with findings suggestive of sideroblastic anemia, even among populations in whom thalassemia mutations are uncommon.