| Thalassmeia is a serious threat to human health,death,disability of hereditary blood disease,belonging to autosomal recessive inheritance.The main cause is the globin gene defects,resulting in reduced or missing globin peptide synthesis,clinical manifestations of varying degrees of progressive hemolytic anemia.Southeast Asia is the region with a high incidence of thalassemia.Unlike the most common hemoglobin sickle(Hb S)in Africa and the Mediterranean,the β-thalassemia of hemoglobin E(Hb E)in Southeast Asia is Main,referred to as βE,mainly due to β-globin gene 26 codon GAG mutations into AAG,resulting in glutamate(Glu)into lysine(Lys),this change activated near the regulation of β-globin gene mRNA shear Of the covert shear sites,the activated covert sites can compete with the normal shear site,so that the normal cut mRNA production decreased,while the abnormal shear of the mRNA instability,resulting in β-globin gene synthesis decreased,while also generating partial variants of mRNA,the latter can guide structural abnormalities but still functional Hb E synthesis.Usually lighter βE in patients with clinical symptoms,however,when βE complexes other types of p-thalassemia,clinical symptoms are very different,and studies have shown that simple β-globin gene mutation is not enough to explain this difference,this suggests that there may be a link between βE and phenotypic factors or phenotypic factors.Therefore,based on the exclusion of β-globin gene mutations,studies were conducted on patients with pE,which can help to further understand the pathogenesis of βE/β-thalassemia,so as to provide a theoretical basis for more accurate genetic counseling based on fetal genotype.Fetal hemoglobin(Hb F)is one of the important factors affecting the clinical symptoms of β-thalassemia,the increase in its expression can be compensated to some extent compensatory p-thalassemia symptoms,clinically,Hb F has been improved as one of the basic strategies for the treatment of β-thalassemia.According to clinical observation,adult body Hb F content with a high number of genetic characteristics,it was found that the quantitative trait loci(QTL)related to the expression of HbF mainly included the HBS1L gene located on the upstream of the HBG2 gene of chromosome 1p15,the HBS1L gene on the 6q23 and the MYB gene and the BCL11A gene on the 2p15.So far,although the molecular mechanism of Hb F expression changes in patients with β-thalassemia and Hb S disease has been reported,studies in patients with pE have not yet been carried out.Based on the above theoretical basis,this paper takes the unique pE patients in Yunnan as the research object,taking Hb F as the starting point,analyzing the related quantitative trait polymorphism,and completed the pE patients with hematopoietic stem cells in vitro culture and red blood cells of the initial orientation induction for the follow-up mechanism and treatment research to provide the carrier,the details are as follows:(1)Polymorphism Analysis of Hb F Associated Quantitative Trait Locus in Patients with pE-thalassemia.A total of 100 samples of βE heterozygous DNA from Yunnan,China were collected,pE homozygous DNA samples in 11 cases,normal(control group)DNA samples in 100 cases,first,the hematological indicators of the three groups were analyzed,the results showed that there were significant differences in the hematological indexes between the control group,βE heterozygous group and pE homozygous group,the mean red blood cell volume(MCV),mean erythrocyte hemoglobin(MCH)and hemoglobin(HGB)showed a decreasing trend,which was consistent with the previous studies,and the content of fetal hemoglobin(Hb F)increased significantly.Then,nine single nucleotide polymorphisms(SNPs)of Hb F quantitative trait loci HBG2/Gγ-XmnI(11p15),HBS1L-MYB(6q23)and BCLllA(2p15)were analyzed(HBG2/Gγ-XmnIrs7482144,rs7937649;BCL11Ars4671393,rsl 1886868,rs766432;HBS1L-MYBrs9399137,rs35959442,rs9402685,rs9376090),chi-square test results show the rs7428144 on Gγ-Xmnl,rs35959442 on HBS1L-MYB and rs766432 and rs4671393 on BCL11A had a significant difference(P<0.05)in the chi-square test(P<0.05),genotyping results showed that,four mutant homozygous rs7482144AA,rs35959442GG,rs4671393GG and rs766432AA were significantly higher in patients with pE than in the control group.Allelic analysis results show,the ratio of mutant alleles rs7482144A,rs35959442G,rs4671393G and rs766432A in the βE heterozygote were higher than those in the normal group.It was confirmed that there was a correlation between βE,Hb F and phenotype of p-thalassemia patients.(2)In vitro culture of hematopoietic stem cells in patients with βE-thalassemia.Peripheral blood of patients with βE-thalassemia was collected and hematopoietic stem cells(HSCs)were sorted by flow cytometry and cultured in serum-free medium supplemented with cytokines,observe the process of cell proliferation,after 6 days of proliferation and growth,Erythropoietin(EPO)was added to induce differentiation,on the third day of the addition of EPO,the cell morphology began to change and began to enter the differentiation phase.These results can provide a carrier for late-stage mechanisms and treatment studies,and ultimately provide new ideas and strategies for prenatal diagnosis,early intervention and treatment of βE/β-thalassemia. |
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