Mild clinical expression of S-<FONT FACE=Symbol>b</font> thalassemia in a Brazilian patient with the <FONT FACE=Symbol>b</font>+ IVS-I-6 (T<FONT FACE=Symbol>®</font>C) mutation

We report on an eight-year-old Brazilian girl with S-b+ thalassemia. The patient had a steady 10.1 g/dl hemoglobin with 57% HbS. Direct sequence analysis of b-globin gene showed her to be heterozygous for the IVS-I-6 (T®C) mutation. This b+ thalassemia mutation, sometimes referred to as the Portuguese type, was found to be associated with the C®T polymorphism at codon 2. In combination with the bS gene, this mutation results in very mild sickle cell disease symptoms.