OBJECTIVETo detect rare types of thalassemia mutations among southern Chinese population.

METHODSPeripheral blood samples from 327 patients from various regions of southern China were collected. The patients were suspected as rare-type thalassemia for their inconsistency between hematological phenotypes and results of routine mutation screening. The samples were further analyzed with GAP-PCR and DNA sequencing.

RESULTSOne hundred and eight cases were diagnosed as rare types of thalassemia. Among whom 10 rare α-globin gene mutations including --THAI, HKα, αααanti3.7, αααanti4.2, -α2.8, -α27.6, CD74 GAC>CAC (Hb Q-Thailand), CD30 (-GAG), CD31 AGG>AAG and CD118 (+TCA), and 12 rare β-globin gene mutations including CD37 TGG>TAG, CD39 CAG>TAG/CD39 CAG>TAG, β II-2 (-T), -90(C>T), -31(A>C), -88(C>T), CD7(-A), CD138(+T), CD89-93 (--AGTGAGCTGCACTG), CD54-58 (-TATGGGCAACCCT), Chinese G γ +(A γδβ)0 and Vietnamese HPFH (HPFH-6) were identified. -88(C>T) (HBB: c.-138C>T) and CD39 CAG>TAG (HBB: c.118C>T) were discovered for the first time in Chinese population. CD7(-A) (HBB: c.23delA) and CD138(+T) (HBB: c.416_417insT) were new types of β-globin gene mutations.

CONCLUSIONThe present study have enriched the mutation spectrum of thalassemia in southern China, which has provided necessary information for its diagnosis.

Humans ; Mutation ; Thalassemia ; genetics ; alpha-Globins ; genetics ; beta-Globins ; genetics

Globin gene induction therapy is a new treatment under study for β-thalassemia. This review summarizes the research progress on the mechanisms of globin gene induction therapy for β-thalassemia and current γ-globin gene induction medicines.
Animals ; Genetic Therapy ; Globins ; genetics ; Humans ; beta-Thalassemia ; therapy

OBJECTIVETo study the effect of liposomal transfection of antisense oligonucleotide (ASON) on the erythroid cell alpha-globin gene in the patients with severe beta-thalassemia, and provide a new idea for beta-thalassemia gene therapy.

METHODSA highly effective ASON targeting alpha-globin gene was transfected into severe beta-thalassemic erythroid cells cultured in vitro by liposomal at an optimal concentration. The expression level of alpha, beta, gamma-globin gene, the level of hemoglobin, and the excess alpha-globin chains precipitates in ASON group and control group were carefully analyzed by quantitative real-time PCR(Q-RT-PCR), high performance liquid chromatography (HPLC), and electron microscope, respectively.

RESULTSThe mRNA expression of alpha-globin gene was significantly lower in ASON group (9.04 +/- 0.29) than in control group (24.23 +/- 0.29) (P<0.01). Simultaneously, the disequilibrium between alpha- and beta-, gamma-globin gene expression was partly modified by ASON, the ratios of ASON group and control group being 0.79 +/- 0.02 and 2.26 +/- 0.06 respectively (P<0.01). HPLC demonstrated that the levels of HbA2 and HbF increased with downregulation of alpha-globin gene in beta-thalassemic erythroid cells, particularly HbF. The precipitates of alpha-globin chains in ASON group were lessened under electron microscope, particularly in early erythroblast while no change in the control group.

CONCLUSIONThe high effective ASON contributes to inhibit the alpha-globin gene expression of severe beta-thalassemic erythroid cells, partly modify the disequilibrium between alpha-, beta- and gamma-globin gene expression and obviously reduce the precipitates of alpha-globin chains in erythroid cells. It might provide a new idea for gene therapy of beta-thalassemia.

Cells, Cultured ; Child ; Genetic Therapy ; Humans ; Liposomes ; Oligonucleotides, Antisense ; genetics ; Transfection ; alpha-Globins ; genetics ; metabolism ; beta-Globins ; metabolism ; beta-Thalassemia ; genetics ; metabolism ; therapy ; gamma-Globins ; metabolism

&beta;-thalassemia is a chronic hemolytic anemia characterized by the reduction or absence of synthesis of &beta;-globin chains because of the &beta;-globin gene mutations. &beta;-thalassemia belongs to the inherited hemoglobin disease, and occurs in some provinces of China, such as in Guangdong, Guangxi, Fujian, its prevalence is about 2%. The treatment of this disease include transfusion, iron chelating agent, hematopoietic stem cell transplantation, splenectomy, induced expression of Fetal Hemoglobin (HbF) and gene therapies. However, the mortality rate of this disease is still higher, thus some new treatments are urgently needed. In recent years, the study was mainly concentrated in 2 aspects: the normal &beta;-globin gene transfer and endogenous γ-globin re-activation. Some studies showed that the expression of miRNAs was dysregulated in &beta;-thalassemia. Some miRNAs could regulate γ-globin at posttranscriptional level, thus, the clarification of relationship between miRNAs and &beta;-thalassemia is expected to provide experimental bases to &beta;-thalassemia therapy. In this review, the induced therapy of γ-globin for &beta;-thalassemia and its relationship with the miRNA are summarized.
China ; Fetal Hemoglobin ; metabolism ; Genetic Therapy ; Humans ; MicroRNAs ; metabolism ; beta-Globins ; genetics ; beta-Thalassemia ; therapy ; gamma-Globins ; therapeutic use

OBJECTIVE: To investigate whether β-globin gene 3'UTR+101G>C (HBB:c.*233G>C) variant has genetic effect and provide basis for gene diagnosis and genetic counseling. METHOD: Whole blood cell analysis and capillary zone electrophoresis (CZE) were used to analyze the hematological indexes. The most frequent 23 mutations in southern Chinese individuals were routinely measured by PCR-flow fluorenscence immunmicrobeads assay. Sanger sequencing was used to detect the other variants of β-globin gene (HBB). RESULTS: In 463 cases, a total of 7 cases with HBB:c.*233G>C variant were detected, among them 4 cases carried other pathogenic variants of HBB gene (2 cases were in trans, 2 cases were in cis), who had typical hematological characteristics of mild β-thalassemia, and 3 cases also carried abnormal hemoglobin variation, but did not have hematological characteristics of β-thalassemia. CONCLUSION The study shows that HBB:c.*233G > C variant has no obvious genetic effect and should be a benign polymorphism.
3' Untranslated Regions ; Hemoglobins, Abnormal/genetics* ; Humans ; Mutation ; beta-Globins/genetics* ; beta-Thalassemia/genetics*

This study was aimed to analyze the hematologic and molecular biologic characteristics of 14 Wenzhou patients with minor beta-thalassemia, to find out the mutation sites responsible for the disease by detecting sequences of PCR products and to analyze the single nucleotide polymorphism. The peripheral blood of patients was collected intravenously and was anticoagulated with EDTA-K(2); then the templates from blood samples were extracted, the related primers were designed for sequencing the products amplified by PCR; finally mutation sites resulting in beta-thalassemia were found through comparison and analysis of sequences. The results indicated that the C-->T heterozygous mutation occurred at the IVS-2 -654 site in 4 cases; the TTCT deficiency appeared at CD41/42 site in 1 case; in 2 sites existed single nucleotide polymorphisms occurring at the 59th site of exon 1 (T/C, CAT/CAC, His) and IVS-2 nt 665 (T/C). It is concluded that single nucleotide polymorphism of minor beta-thalassemia patients born in Wenzhou had specificity, this study found too kinds of gene mutations which are IVS-2 -654 C-->T heterozygous mutation and CD41/CD42 site-TTCT deficiency.
Base Sequence ; China ; Humans ; Mutation ; Polymorphism, Single Nucleotide ; beta-Globins ; genetics ; beta-Thalassemia ; genetics ; metabolism

β-thalassemia is a monogenetic inherited hemolytic anemia, which results in a series of pathophysiological changes due to partial or complete inhibition of the synthesis of β-globin chain. The curative therapy for this disease is to reconstitute hematopoiesis, and transplantation with genetically modified autologous hematopoietic stem cells can avoid the major difficulties of traditional allogeneic hematopoietic stem cell transplantation，such as HLA matching and immune rejection. β-thalassemia gene therapy strategies mainly include gene integration and genome editing. The former relies on the development of lentiviral vectors and adds a fully functional HBB gene to the chromosome; the latter rapidly develops with the research of specific nuclease which can repair the HBB gene in situ. In this review, the latest progress of the two strategies in gene therapy of β-thalassemia is summarized.
Gene Editing ; Genetic Therapy ; Genetic Vectors ; Humans ; beta-Globins/genetics* ; beta-Thalassemia/therapy*

OBJECTIVE: To determine the composition and distribution of beta-thalassemia-associated genotypes in Liuzhou area of Guangxi, China. METHODS: From January to December 2017, 13 847 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 beta-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 beta-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/aa, -a3.7/aa, aCSa/aa, -a4.2/aa. Through Sanger sequencing, rare genotypes such as beta-32/betaN, betaCD41-42/betaIVS-II-5 and betaCD30/betaN were detected. CONCLUSION Liuzhou area has a high incidence of beta-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 beta-thalassemia in this area.
China ; Female ; Genetic Counseling ; Genetic Variation ; Genotype ; Humans ; Mutation ; Pregnancy ; Prenatal Diagnosis ; alpha-Globins ; genetics ; beta-Globins ; genetics ; beta-Thalassemia ; diagnosis ; genetics

OBJECTIVETo identify a rare transcription mutation (C-->T) at position -90 of the beta-globin gene previously unreported in the beta-thalassemia carriers from a Chinese family.

METHODSIn phenotype analysis, standard hematological techniques were used to measure RBC counts and Hb concentration. Reverse dot blot (RDB) analysis, which can simultaneously detect 18 known types of beta-thalassemia mutations in Chinese, was used to scan beta-globin gene mutations. DNA sequence analysis of the entire human beta-globin gene was performed to characterize the underlying causative mutation of the sample and to identify its genotype. A semi-quantitative RT-PCR method was used to measure beta-globin gene expression in the form of mRNA from the subjects.

RESULTSThe proband, his brother and his mother presented a typical beta-thalassemic trait with reduced mean corpuscular volume (MCV, 68.2-73.6 fL) and elevated level of Hb A(2) (5.7%-6.4%) but no known beta-thalassemia mutations were found in the samples by RDB analysis. DNA sequencing of the beta-gene region of these three samples revealed heterozygosity for the C-->T substitution at position -90 within proximal CACCC box of the beta-globin gene promoter element, which was previously unreported in the Chinese population. Analysis of mRNA from the positive carriers demonstrated that the mutant beta-globin gene significantly reduced beta-globin transcription (mutants: 2.233 +/- 0.01 vs normal: 3.779+/-1.19; 95%CI: 3.060, 4.499), showing a level comparable with that of the other beta-thalassemia heterozygotes (2.110+/-0.53, 95%CI: 1.732, 2.488).

CONCLUSIONA rare transcriptional mutation that led to beta-thalassemia in Chinese population has been characterized. The findings enrich knowledge of the mutation spectrum of beta-thalassemia.

Adult ; Female ; Globins ; genetics ; Humans ; Mutation ; Transcription, Genetic ; beta-Thalassemia ; genetics

OBJECTIVE: To study the hematologic and molecular features of 14 patients with hemoglobin (Hb) variants, so as to provide reference data for its laboratory screening. METHODS: A total of 1 029 samples were screened by high performance liquid chromatography (HPLC) on the Bio-Rad VariantⅡHPLC system. GAP-PCR and reverse dot blot (RDB) were used to detect common mutation of α and β globin gene in Chinese. DNA sequencing for α and β globin gene was simultaneously performed in samples with abnormal spectrum peak and negative thalassemia gene. RESULTS: In 1 029 samples, 10 types of structural Hb variants were detected in14 cases (1.36%), including 1 case of Hb E / β- thalassemia, 1 case of Hb E /α- thalassemia (HbH disease), 2 cases of HbG-Taipei, 2 cases of Hb Q-Thailand, 2 cases of Hb Youngstown, 1 case of Hb Guangzhou-Hangzhou, 1 case of Hb M-Boston, 1 case of Hb G-Siriraj, 1 case of Hb J-Baltimore, 1 case of Hb J-Sicilia and 1 case of Hb Tamano. CONCLUSION The occurrence of abnormal structural Hb variants with many genotypes in Shanghai is unique. Except for Hb E, Hb Youngstown, and Hb M-Boston, other types of heterozygous are normal in phenotypes, and symptoms such as hemolysis and anemia often occur when other diseases are combined.
China ; Genotype ; Hemoglobins, Abnormal/genetics* ; Humans ; Phenotype ; alpha-Thalassemia ; beta-Globins/genetics*