Relationship Between Genetic Variation Of Modified Gene HBG2,BCL11A,HBS1L-MYB And KLF1 And Hemoglobin Hb F Expression In β-thalassemia Patients In Yunnan

Objectives: Analyzing the association of HBG2,BCL11 A,HBS1L-MYB polymorphisms and KLF1 mutations with fetal hemoglobin(Hb F)in Yunnan popu Lation;The modifying effect of HBG2,BCL11 A,HBS1L-MYB polymorphisms and KLF1 mutations on clinical appearances of intermedia and major β-thalassemia(homozygotes or compound heterozygotes for β0 or β+ genes,hemoglobin E/β-thalassemia patients)in Yunnan popu Lation.Methods: The patient’s peripheral blood samples are collected,and Hb parameters were determined using CAPILLARYS 2 Flex System.The patients signed informed consent,and we collecting the blood sample of Hb F higher than 5%;Divided into different groups according to Hb F level: 5%≤Hb F≤10% group,10%≤Hb F≤20%group,Hb F >20%.And according to the quantatives of samples of Hb F higher than 5.0%that peripheral blood samples of healthy and unrelated adults were randomly selected at 1:1 in Yunnan population.Collecting blood samples of patients that thalassemia genes detected as homozygotes(β0/β0)or compound heterozygotes [β0/β+,β+/β+,(Aγδβ)0] or Hb E/β-thalassemia(βE/β0,βE /βE).Genomic DNA was extracted from these peripheral blood samples.The concentration of DNA was performed using NANODROP 2000(Thermol).The genotype of rs7482144 polymorphism site of HBG2 gene,rs11886868 and rs766432 polymorphism sites of BCL11 A gene was analysed using PCR–RFLP;The genotype of rs9399137 and rs66650371 polymorphism sites of HBS1L-MYB gene was analysed using ARMS;8 mutation sites(c.13G>A,c.41T>C,c.519-c.525 dup CGGCGCC,c.892G>C,c.895C>G,c.913+1G>A,c.1001C>G and c.1022G>A)of the KLF1 genewas analysed using sanger sequencing.Results: The association study between polymorphism sites(rs7482144,rs11886868,rs766432,rs9399137 and rs66650371)and different Hb F values : 5%≤Hb F≤10% group finding P value(1.69E-14,0.205,2.35E-04,1.00E-21 and 1.59E-22;5%≤Hb F≤10% group finding P value: 0.019,0.131,0.053,2.05E-06,8.47E-08;Hb F>20% group finding P value: 0.111,0.427,0.192,0.227,0.062,respectively).Sample495,thier 8 sites(c.13G>A,c.41T>C,c.519-525 dup CGGCGCC,c.892G>C,c.895C>G,c.913+1G>A,c.1001C>G and c.1022G>A)of KLF1 gene was analysed using sanger sequencing.Unfounded association mutation of 8 sites of the KLF1 gene.Intersting,however,215 samples of Hb F higher than 5.0%,Three variaes were detected to c.544T>C sites T/C heterozygotes for 3,c.901C>T sites C/T heterozygotes for 1,and c.902G>A sites G/A heterozygotes for 2.The association study between KLF1 gene mutations and different Hb F values: 5%≤Hb F≤10% group and 10%≤Hb F≤20% group finding P value 0.003,0.005,respectively.Conclusion: Our results demonstrated the association rs7482144,rs9399137 and rs66650371 polymorphism sites with 5%≤Hb F≤20% levels,the association rs766432 with 5%≤Hb F≤10%;however,unrelated rs11886868 with Hb F.The association three mutations c.544T>C,c.901C>T and c.902 G>A of KLF1 gene with 5%≤Hb F≤20%.Mutant genotypes of rs7482144 loci may alleviate clinical symptoms in patients withβ-thalassemia.