Abstract: Objective To investigate the gene carrying rate, mutation spectrum and frequency of thalassemia in the childbearing age population of Dai nationality in Yingjiang County, Dehong Prefecture, Yunnan Province, China and to provide a theoretical basis for strategy maiming for the prevention and control of thassemia birth defects. Methods Totally 400 cases of childbearing age population of Dai nationality in Yingjiang County were subjected to routine blood testing, capillary electrophoresis, and next generation sequencing. Results Among the 400 cases 219(54.75%) thalassemia gene carriers were found. There were 133(33.25%) carriers having α-thalassaemia gene. The most common genotype was -α^3.7, followed by--^SEA and -α^4.2. There were 47(11.75%) carriers of β-thalassemia gene, and the mutation type CD26 (G＞A) was the most common type. There were 39(9.75%, 39/400) carriers of composite α and β thalassemia. According to comparative analysis of the hematological characteristics of various α-thalassemias, mean corpsular hemoglobin(MCH) of --^SEA and Hb A₂ of α^CSα were relatively low. According to comparative analysis of the hematological characteristics of β-thalassemia, mean corpusular volume(MCV) of CD17 (A＞T) was relatively low. Conclusions The carrying rate of thalassaemia in Yingjiang County is 54.75%, indicating it is a high incidence area of thalassaemia. The most common types are -α^3.7 and CD26 (G＞A). The results reported here may provide evidence for genetic counseling in areas with high incidence of thalassaemia.

Key words: thalassemia, hematological characteristics, genotype, Dai nationality