Mild clinical expression of S-b thalassemia in a Brazilian patient with the b+ IVS-I-6 (T？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.