Next-generation sequencing improves molecular epidemiological characterization of thalassemia in Chenzhou Region, PR China

Objectives Thalassemia is a highly prevalent monogenic inherited disease in southern China. It is important to collect epidemiological data comprehensively for proper prevention and treatment. Methods In this study, blood samples collected from 15 807 residents of Chenzhou were primarily screened by hematological tests. A total of 3973 samples of suspected thalassemia carriers were further characterized by combined next-generation sequencing (NGS) and Gap-PCR. Results In total, 1704 subjects were diagnosed as thalassemia carriers with a total prevalence rate of 10.78%, including 943 alpha-thalassemia carriers, 708 beta-thalassemia carriers, and 53 composite alpha and beta-thalassemia carriers. The prevalence rates of alpha-thalassemia, beta-thalassemia, and composite alpha and beta-thalassemia were 5.97%, 4.48%, and 0.34%, respectively. Meanwhile, we characterized 19 alpha-thalassemia variations and 21 beta-thalassemia variations in thalassemia carriers. Approximately 2.88% of thalassemia carriers would be missed by traditional genetic analysis. In addition, four novel thalassemia mutations and one novel abnormal hemoglobin mutation were identified. Conclusions Our data suggest a high prevalence of thalassemia and a diverse spectrum of thalassemia-associated variations in Chenzhou. Also, combined NGS and Gap-PCR is an effective thalassemia screening method. Our findings might be helpful for prevention and treatment of thalassemia in this region.