Genotype Spectrum and Hematological Features of β–Thalassemia with or without Different Forms of α-Thalassemia in Shenzhen

Background: The effects of different forms of α–thalassemia on β-thalassemia phenotype has not been clearly described thus far. Methods: Genotype spectrum and hematological features of 873 female diagnosed as β-thalassemia carriers with or without different forms of α-thalassemia was retrospectively analyzed. Results: Thirteen kinds of genotypes were found in the 755 β-thalassemia carriers, including four kinds of β+-thalassemia, eight kinds of β0 -thalassemia and one kind of βE-thalassemia. The values of hemoglobin (Hb), mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) decreased and red blood cell (RBC) increased in the order of βE, β+- and β0 group (p＜0.05). Nine genotypes were determined from the 43 carriers with concurrent α- and β+-thalassemia and seventeen genotypes were determined from the 75 carriers with concurrent α- and β0 -thalassemia. Significant higher Hb, MCV and MCH values were noted in β+–thalassemia or β0–thalassemia co-inherited with α+-thalassemia or α0-thalassemia as compared to the only β+–thalassemia or β0–thalassemia heterozygosity with normal alpha globin gene (p＜0.05). Moreover, the values of Hb, MCV and MCH increased much more when β0–thalassemia co-inheritance of α0-thalassemia than that of α+-thalassemia (p＜0.05). Conclusion: The β-thalassemia presented diverse molecular heterogeneity and hypochromic microcytosis at various degrees. Co-inherited with α–thalassemia could alleviate phenotype of anemic in β+- or β0-thalassemia, and β0-thalassemia demonstrated milder phenotype with two deletion or mutation in α-globin gene than one.