Analysis of β globin gene variants in Liuzhou area of Guangxi

Abstract

Objective To determine the composition and distribution of β-thalassemia-associated genotypes in Liuzhou area of Guangxi, China. Methods From January to December 2017, 13847 individuals who came for premarital examination, maternity examination or health check were recruited with informed consent. The subjects were analyzed by reverse dot blotting (RDB) for 17 common β-thalassemia-associated variants among the Chinese population. Individuals with inconsistent results by blood test, electrophoresis, and RDB were subjected to Sanger sequencing to detect rare variants of the beta globin gene. Results In total 2098 individuals were found to harbor β-thalassemia-associated variants, which included 2075 heterozygotes (98.90%), 12 compound heterozygotes (0.57%) and 11 homozygotes (0.52%). CD41-42 (48.43%) and CD17 (31.45%) were the most common variants. Three hundred and thirty eight-individuals were found to also carry heterozygous variants of the alpha globin gene, with the most common types being -SEA/αα, -α3.7/αα, αcs α/αα, -α4, 2/αα. Through Sanger sequencing, rare genotypes such as β-32/βN, βCD41-42/βIVS-II-5 and βcd3o/βnwere detected. Conclusion Liuzhou area has a high incidence of R-thalassemia, but with a complex variant spectrum and clinical phenotypes different from other regions. Genetic counseling and prenatal diagnosis for the carrier population is crucial for the reduction of the related birth defects. Our result may provide valuable information for the prevention and control of R-thalassemia in this area.