RESUMO
Beta-Thalassemias pose by far be most important global public health problem, hence a good undertaning of their natural history and the factors that can modifytheir clinical phenotype is a must to understand the heterogeneity in both phenotype and genotype. Sixty-two beta-thalassima patients classified clinically into severe, late onset and intermedia phenotyps were studied for beta-globin gene mutations, alpha-globin gene [-3.7] deletion and-185 G-T gamma-gobin gene Xmnl polymorphism. Twenty one different beta-thalassemia genotypes were found, alpha globin gene deletions were dtcte in 3.2% of patients and gamma-globin gene XmnI polymorphsm in 4.8% of the studied. Cases cointheritance of alpha delectation and gamma-globin gene polymorphism were associated with intermedia phenotype [in 5.7% of intermedia cases]. Disease severity could not be explained by the beta-globin gene mutation in 20.9% of patients, further genetic studies are needed