[Analysis of Thalassemia Gene Mutation Types and Ethnic Distribution Characteristics in Hechi Area, Guangxi]

Objective: To investigate the genotype, mutation type, and ethnic distribution characteristics of thalassemia in the population of Hechi area, Guangxi, and to provide a reference basis for prevention and control of thalassemia and eugenic counseling in the region.

Methods: Gap-polymerase chain reaction (gap-PCR) and reverse dot blot (RDB) were used for genetic testing on suspected thalassemia persons, and the results were analyzed.

Results: Among 29 136 samples, a total of 17 016 (58.40%) positive samples for thalassemia genes were detected, with a higher detection rate in males than in females (χ²=49.917，P < 0.001). The detection rates of thalassemia genes were significant different among Zhuang, Han, Yao, Mulao, and Maonan ethnic groups (χ²=546.121, P < 0.001). The α-thalassemia genotypes were mainly --^SEA /αα (16.67%), -α^3.7/αα (8.90%), α ^CSα/αα (6.00%). Additionally, four rare genotypes were detected, including -- ^THAI/αα (47 cases), HKαα/αα (2 cases), --^SEA /-α ^21.9 (2 cases), and -- ^THAI/α^CSα (1 case). The β-thalassemia genotypes were mainly β ^CD17/β^N (7.49%), β^CD41-42/β^N (6.70%), β^CD71-72/β^N (0.44%). 108 cases of moderate and severe β-thalassemia were detected, of which 81 cases had a history of blood transfusion, the transfusion frequency of 60 cases was more than 10 times/year, and 10 cases received bone marrow transplantation.

Conclusion: Thalassemia in Hechi area is predominantly deletion type --^SEA /αα, the detection rate of thalassemia in ethnic minorities is higher than that in Han population. In this area, moderate and severe β-thalassemia have certain incidence, these patients mostly need regular blood transfusion and iron removal treatment, and very few patients have received bone marrow transplantation. This study provides a certain reference basis for prevention and control of thalassemia and eugenic counseling in the region.