Epidemiological study of thalassemia in the Buyi population of Qiannan Prefecture, Guizhou Province, China based on third-generation sequencing

This genetic epidemiological study aimed to investigate the prevalence of various types of thalassemia among the Buyi population in Qiannan Prefecture, Guizhou Province, China. A total of 1,003 Buyi individuals from five regions in Qiannan Prefecture were enrolled for this study. Peripheral blood samples were collected for routine blood testing and hemoglobin electrophoresis. Thalassemia-related variants were identified using third-generation sequencing (TGS). The overall carrier rate of thalassemia in the Buyi population was 22.83% (229/1003). The carrier rates of α-thalassemia, β-thalassemia, and δ-thalassemia were 16.15% (162/1003), 6.68% (67/1003), and 1.20% (12/1003), respectively. The most common α-thalassemia genotype was -α^3.7/αα (32.89%), followed by --^SEA/αα (25.66%). Structural variants ααα^anti3.7/αα and ααα^anti4.2/αα were also identified, accounting for 5.26% and 1.32% of the α-globin gene variant genotypes, respectively. For β-thalassemia, the most frequent genotypes were β^{CD17(AAG> TAG)}/β^N (45.61%) and β^{CD41/42(-CTTT)}/β^N (43.86%), with β⁰-thalassemia accounted for 96.49% of β-thalassemia. Thalassemia is highly prevalent in the Buyi population of Qiannan Prefecture. The variant frequencies observed in this population differ from those in other populations in China. TGS proves to be an effective tool for thalassemia screening, particularly in regions with high prevalence.