Deletional a-thalassemia 1 gene detection and hematological analysis in carrier with β-thalassemia

Abstract

There are high prevalence of β-thalassemia and α-thalassemia in the upper Northern Thailand. Thus, the interaction between β-thalassemia and α-thalassemia can be occurred. The aim of this study was to analyze the incidence of gene interaction between α-thalassemia 1 SEA and THAI type deletions in 317 β-thalassemia carriers who were living in 3 provinces in upper Northern Thailand. The α-thalassemia 1 SEA and THAI type deletions were diagnosed using gap-PCR. The results showed that the double heterozygous of β-thalassemia and α-thalassemia 1 SEA type deletion was observed in 32 samples (10.1%). The hematological parameters, red blood cell indices and Hb A2 levels were compared among the two groups of β-thalassemia carriers with and without α-thalassemia 1 SEA type deletion. The RBC, Hb, Hct, MCHC, RDW-CV and HbA2 levels of the two groups were not significant difference (p > 0.05) while the MCV and MCH of β-thalassemia carriers with α-thalassemia 1 SEA type deletion were significantly higher (p< 0.001) than those of β-thalassemia carriers without α-thalassemia 1 SEA type deletion. These results indicated that there is a high prevalence of β-thalassemia and α-thalassemia interaction within the area with high frequency of β-thalassemia and α-thalassemia. Therefore, the default of α-thalassemia 1 diagnosis in β-thalassemia carriers can be a cause of Hb Bart’s hydrops fetalis. The hematological parameters of β-thalassemia carriers with and without α-thalassemia 1 SEA type deletion were similar. Therefore, the gene analysis of α-thalassemia 1 should be performed in all β-thalassemia carriers.