Frequencies of CD39, IVS1-1, IVS1-6 and IVS1-110 mutations in beta-thalassemia carriers and their influence on hematimetric indices

ABSTRACT Introduction: Beta-thalassemia is caused by a deficient synthesis of the ß-chain of hemoglobin, which leads to a chronic, microcytic and hypochromic anemia. More than 200 mutations have already been associated with this type of thalassemia, and their frequencies may vary according to the population. Objectives: The objectives of this study were to determine the frequencies of CD39, IVS1-1, IVS1-6 and IVS1-110 mutations in people with beta-thalassemia from the city of Franca, São Paulo, and to evaluate the influence of the genotypes on hematological alterations. Methods: Venous blood samples were collected from 25 volunteers previously diagnosed with beta-thalassemia. Complete blood counts (CBC) were performed, and the identification of the mutations was carried out using the polymerase chain reaction (PCR). Results: The CD39 mutation was found in 11 (44%) individuals, followed by IVS1-6 (9; 36%) and IVS1-110 (4; 16%). One patient (4%) did not present any of these mutations. IVS1-6 mutation was inversely correlated to red cell distribution width (RDW) (rs = -0.44; p = 0.034), and CD39 was correlated to lower mean corpuscular volume (MCV) (rs = -0.44; p = 0.034). Multivariable linear regression models showed that the CD39 mutation carriers have lower levels for hemoglobin (ß = -0.61; p = 0.044) and hematocrit (ß = -2.1; p = 0.018). Conclusion: The results showed a high frequency of the CD39 mutation in the city of Franca, and the correlations observed between the presence of CD39 mutation and the hematological alterations suggest a genotype influence on the phenotype of beta-thalassemia, which would contribute to the clinical variations of this hemoglobinopathy.