Prevalence and Genetic Analysis of β-Thalassemia in the Dali Bai Autonomous Prefecture of the Yunnan Province, China

Background: β-Thalassemia is the most common monogenetic hemolytic hemoglobin-associated disease in the south of China; the distribution of genetic mutations associated with this condition varies according to geographic regions. This study investigated the prevalence and distribution of β-thalassemia-associated mutations across different ethnic groups in the Dali Bai Autonomous Prefecture of the Yunnan Province, China. Methods: This cross-sectional study included 4723 participants (15-45 years old) who volunteered for thalassaemia screening from the Dali Bai Autonomous Prefecture from May 2017 to October 2020. Cellulose acetate membrane electrophoresis was used to screen for β-thalassemia carriers. Genotypic analyses was performed using polymerase chain reaction-based reverse dot blotting and DNA sequencing. Results: The overall prevalence of β-thalassemia in the study population was 2.01%. The genotypic analyses showed the presence of four types of mutations in the β-globin gene: CD26 (GAG→AAG), CD56 (GGC→GAC), IVS-II-81 (C→T), and CD121 (GAA→CAA). In contrast to previous studies from other regions of Yunnan Province, our results showed that the prevalence of CD26 mutations was significantly higher than that of the other mutations. Conclusion: Our data suggests that the Dali Autonomous Prefecture is an area with a high prevalence of β-thalassemia. Moreover, CD26 was the only β-thalassemia mutation that we have detected. Moreover, the vast majority of the β-thalassemia mutations observed were CD26.