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1.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(3): 918-926, 2020 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-32552958

RESUMO

OBJECTIVE: To investigation the types and frequencies of thalassemia gene mutations in pregnant population in Nanping area of Fujian Province, so as to provide a basis for prevention and control of birth children with moderate and severe thalassaemia in this area. METHODS: The genotyping of α and ß thalassemia was performed using the gap-PCR (gap-PCR) technique combined with reverse dot blot (RDB). The genotyping test was performed by Gap-PCR for three rare deficient thalassemia. The cases with negative detection were further detected by Sanger sequencing method, so as to identify rare α or ß thalassemia mutation. RESULTS: 1120 specimens were genotyped for thalassemia, out of them 547 thalassemia genes were determined. The detection rate was 48.8% (547/1120). 340 specimens were diagnosed as α thalassemia, and the detection rate was 30.6%, including 266 cases of --SEA/αα, 44 cases of -α3.7/αα, 12 cases of -α4.2/αα, 8 cases of ααQS/αα,. 3 cases of Hb H disease ( 2 cases of --SEA/-α3.7, 1 case of --SEA/-α4.2), 2 cases of ααCS/αα, 2 cases of ααWS/αα, 1 case of -α3.7/-α3.7, and 1 case of -α3.7/ααQS. Also, they contain 11 cases of rare α thalassemia, 8 kinds of rare types of α thalassemia mutations in combination, such as 4 cases of ααIVS-II-55 (T→G) in α1/αα, 1 case of ααIVS-I-62 (C→T) in α1/αα, 1 case of ααCD106(CTG→GTG)in α2/αα, 1 case of ααHBA2:c.-24C>G/αα, 1 case of ααIVS-II-55 (T→G) in α1/ααIVS-II-55 (T→G) in α1, 1 case of ααIVS-II-55 (T→G) in α1/ααIVS-II-119 (G;+CTCGGCCC) in α2, 1 case of ααIVS-II-88 (G→A) in α2/αα, and 1 case of --THAI/αα. Among them, 5 α mutation sites were first reported, namely ααIVS-I-62 (C→T) in α1, ααIVS-II-55 (T→G) in α1, ααIVS-II-119 (G; +CTCGGCCC ) in α2, ααIVS-II-88 (G→A) in α2 and ααCD106 (CTG→GTG) in α2; 2 α thalassemia mutation sites: ααHBA2: c.-24C>G and --THAI were detected again in the Chinese population, respectively. 188 specimens were diagnosed as ß thalassemia with a detection rate of 16.8%. Among them, 68 cases of ßIVS-II-654/ßN, 47 cases of ßCD41-42/ßN, 20 cases of ßCD17/ßN, 17 cases of ß-28/ßN, 7 cases of ßCD27-28/ßN, 7 cases of ßE/ßN, 3 cases of ßCD71-72/ßN and 2 cases of ßCD43/ßN. And 17 cases were diagnosed as rare ß thalassemia, 8 kinds of rare types were ß thalassemia mutations in combination. There were 4 cases of ßIVS-II-81 (C→T)/ßN, 3 cases of ßHb J-Bangkok/ßN, 3 cases of ßHb New York/ßN, 2 cases of ß-96 (G→T)/ßN, 2 cases of ßIVS-II-806 (G→C)/ßN, 1 case of ßCodons 8/9/ßN, 1 case of ßHb G-Coushatta/ßN, 1 case of ßIVS-II-827 (A→T)/ßN. Among them, 3 ß thalassemia mutation sites were reported for the first time, namely ß-96 (G→T), ßIVS-II-806 (G→C) and ßIVS-II-827 (A→T); it was found that in the Chinese population as ßCodons 8/9, ßHb G-Coushatta, ßHb J-Bangkok, ßHb New York, and ßIVS-II-81 (C→T), respectively. 19 cases were diagnosed as αß-complex thalassemia, out of which 15 types of thalassemia mutation combinations were detected. They contain 2 cases of rare αß-complex thalassemia, which are ααIVS-II-55 (T→G)/αα complex ßIVS-II-81 (C→T)/ßN, ααIVS-II-65 (G→A) in α1/αα complex ßHb G-Coushatta/ßN. CONCLUSION: The types of thalassemia gene mutations in Nanping area of Fujian province are genetically heterogeneous. The prevention and control strategies of thalassaemia in this area should be based on the prevention and treatment of common α thalassemia and ß thalassaemia. And the attention should be paid to the types of rare and unknown gene mutations using screening and testing method.


Assuntos
Talassemia alfa , Talassemia beta , China , Feminino , Genótipo , Humanos , Mutação , Gravidez , Tailândia , Talassemia alfa/genética , Talassemia beta/genética
2.
Mol Genet Genomics ; 295(2): 505-514, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31897801

RESUMO

α-thalassemia is an inherited blood disorder commonly caused by deletions or point mutations involving one or both α-globin genes. Recent studies shed new light on the critical role of upstream enhancers multi-species conserved sequences (MCSs) in the ordered regulation of α-globin gene expression. Herein, we reported two unrelated probands with deletions in α-globin genes and MCSs, respectively. The proband from Family A is a compound heterozygote carrying a known α+ mutation (-α3.7) and a novel 60.2 kb deletion causing the absence of both α-globin genes. The proband from Family B, on the other hand, is a compound heterozygote with a known α0 mutation (--SEA) and a novel deletion involving only upstream regulatory elements MCS-R1, R2 and R3, while the α-globin genes remain intact. Notably, both these two patients suffered varied extent of anemia, indicating that the loss of enhancer elements could equally lead to reduced synthesis of α-globin. Upon these observations, we then confirmed the exact breakpoints of these two novel deletions using a targeted next-generation sequencing (NGS) previously established by our group, which may enable further elucidation of the rearrangement mechanisms on these deletions and functional dissection of MCSs. Taken together, our study reports a reliable NGS-based molecular screening approach for accurate identification of copy number variations (CNVs) in the α-globin cluster and the genetic diagnosis of these two probands may help to extend the spectrum of α-thalassemia mutations in Chinese population.


Assuntos
Elementos Alu/genética , Anemia/genética , alfa-Globinas/genética , Talassemia alfa/genética , Adulto , Anemia/sangue , Anemia/patologia , Variações do Número de Cópias de DNA/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Família Multigênica/genética , Linhagem , Mutação Puntual/genética , Deleção de Sequência/genética , Talassemia alfa/sangue , Talassemia alfa/patologia
3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(1): 33-36, 2020 Jan 10.
Artigo em Chinês | MEDLINE | ID: mdl-31922592

RESUMO

OBJECTIVE: To explore hematological and genotypic characteristics of patients with hemoglobin E (Hb E) disorders from Yunnan Province. METHODS: One hundred individuals with Hb E disorders indicated by high performance liquid chromatography (HPLC) were subjected to genetic testing through multiple gap-PCR and reverse dot-blotting analysis. RESULTS: All patients were found to harbor a mutation to the 26th codon of the ß -globin chain (HBB: c.79G>A). Ninety patients were heterozygotes, and 10 co-inherited c.79G>A and an α -thalassemia mutation (7 α α /-α3.7, 2 α α /--SEA and 1 -α 3.7/-α3.7). Hematological characteristics of the heterozygotes were: Hb A2 (26.02±3.64)%, Hb F(1.35±1.25)%, MCV(78.83±4.68) fl, MCH(26±1.54) pg, MCHC (329.65±10.73) g/L, HGB (141.08±16.53) g/L, while that of the co-inherited cases was decided by the type of α -thalassemia mutation. CONCLUSION: Hb E can be effectively detected by HPLC. The type of α -thalassemia mutations will determine hematological features of co-inherited cases. Hb E disorders may be missed by relying only on routine blood test upon prenatal screening.


Assuntos
Hemoglobina E , Talassemia alfa , China , Feminino , Genótipo , Hemoglobina E/genética , Humanos , Mutação , Gravidez , Talassemia alfa/genética , Globinas beta/genética
4.
BMC Med Genet ; 21(1): 6, 2020 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-31906886

RESUMO

BACKGROUND: Thalassemia is a group of inherited hemoglobic disorders resulting from defects in the synthesis of one or more of the hemoglobin chains, which is one of the most prevalent inherited disorders in southern China. Only few studies reported the molecular characterization of α- and ß-Thalassemia in Hubei Province in the central of China. METHODS: A total of 4889 clinically suspected cases of thalassemia were analyzed by Gap-PCR, PCR-based reverse dot blot (RDB). RESULTS: 1706 (33.8%) subjects harbored thalassemia mutations, including 539 (11.0%) subjects with α-thalassemia, 1140 (23.3%) subjects with ß-thalassemia mutations, and 25 (0.51%) subjects with both α- and ß-thalassemia mutations. Seven genotypes of α-thalassemia mutations and 29 genotypes of ß-thalassemia mutations were characterized. --SEA/αα (66.05%), -α3.7/αα (24.12%), and -α4.2/αα (3.71%) accounted for 93.88% of the α-thalassemia mutations. ßIVS-II-654/ßN, ßCD41-42/ßN, ßCD17/ßN, ßCD27-28/ßN, ßCD71-72/ßN, ß - 28/ßN, ß - 29/ßN, ßCD43/ßN, ßE/ßN, accounting for 96.40% of all ß-thalassemia genotypes. Furthermore, mean corpuscular volume (MCV) and mean corpuscular Hb (MCH) were sensitive markers for both ß-thalassemia and α-thalassemia with --SEA/αα, but not -α3.7/αα and -α4.2/αα. CONCLUSIONS: Our data indicated great heterogeneity and extensive spectrum of thalassemias in Hubei province of China.


Assuntos
Genética Populacional , Hemoglobinas/genética , Talassemia alfa/genética , Talassemia beta/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China , Feminino , Heterogeneidade Genética , Genótipo , Hemoglobinas/biossíntese , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Mutação , Adulto Jovem , Talassemia alfa/epidemiologia , Talassemia beta/sangue , Talassemia beta/epidemiologia
5.
J Clin Pathol ; 73(8): 488-492, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31980563

RESUMO

AIMS: Thalassaemia is one of the most common genetics disorders in the world, especially in southern China. The aim of the present study was to investigate the feasibility of combining the gap-PCR and next-generation sequencing (NGS) for thalassaemia carrier screening in the Chinese population. METHODS: Blood samples were obtained from 944 prepregnancy couples; thalassaemia carrier screening was performed by using a routine haematological method and a combination of gap-PCR and NGS method. RESULTS: We found that the α thalassaemia carrier rate was 11% (207/1888); the ß thalassaemia carrier rate was 3.7% (70/1888); the composite α thalassaemia and ß thalassaemia carrier rate was 0.4% (8/1888). We also identified seven novel mutations, including HBA1: c.412A>G, -50 (G>A), HBB: c.*+129T>A, HBB: c.-64G>C, HBB: c.-180G>C, HBB: c.*+5G>A and HBB: c.-113A>G. By comparing the combined gap-PCR and NGS method, the MCV+MCH and HbA2 detection strategy showed a lower sensitivity of 61.05% (105/172) and a higher missed diagnosis ratio of 38.95% (67/172) for α thalassaemia mutations. The sensitivity was improved with the MCV+MCH and HbA2 detection screen when compared with MCV+MCH detection for ß thalassaemia (98.51% vs 85.90%). CONCLUSIONS: Our study suggests the combined gap-PCR and NGS method is a cost-effective method for the thalassaemia carrier screening, particularly for the α thalassaemia mutation carriers.


Assuntos
Talassemia alfa/genética , Talassemia beta/genética , Adulto , China , Feminino , Triagem de Portadores Genéticos/métodos , Triagem de Portadores Genéticos/normas , Genótipo , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Mutação/genética , Reação em Cadeia da Polimerase/métodos , Cuidado Pré-Concepcional , Sensibilidade e Especificidade , Adulto Jovem , alfa-Globinas/genética , Globinas beta/genética
6.
PLoS Biol ; 18(1): e3000594, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31895940

RESUMO

Alpha thalassemia/mental retardation syndrome X-linked chromatin remodeler (ATRX), a DAXX (death domain-associated protein) interacting protein, is often lost in cells using the alternative lengthening of telomeres (ALT) pathway, but it is not known how ATRX loss leads to ALT. We report that ATRX deletion from mouse cells altered the repair of telomeric double-strand breaks (DSBs) and induced ALT-like phenotypes, including ALT-associated promyelocytic leukemia (PML) bodies (APBs), telomere sister chromatid exchanges (T-SCEs), and extrachromosomal telomeric signals (ECTSs). Mechanistically, we show that ATRX affects telomeric DSB repair by promoting cohesion of sister telomeres and that loss of ATRX in ALT cells results in diminished telomere cohesion. In addition, we document a role for DAXX in the repair of telomeric DSBs. Removal of telomeric cohesion in combination with DAXX deficiency recapitulates all telomeric DSB repair phenotypes associated with ATRX loss. The data reveal that ATRX has an effect on telomeric DSB repair and that this role involves both telomere cohesion and a DAXX-dependent pathway.


Assuntos
Proteínas Correpressoras/fisiologia , Quebras de DNA de Cadeia Dupla , Reparo do DNA/genética , Chaperonas Moleculares/fisiologia , Troca de Cromátide Irmã/genética , Telômero/genética , Proteína Nuclear Ligada ao X/fisiologia , Animais , Células Cultivadas , Embrião de Mamíferos , Feminino , Células HeLa , Humanos , Masculino , Retardo Mental Ligado ao Cromossomo X/genética , Retardo Mental Ligado ao Cromossomo X/patologia , Camundongos , Camundongos Knockout , Transdução de Sinais/genética , Telômero/metabolismo , Homeostase do Telômero/genética , Talassemia alfa/genética , Talassemia alfa/patologia
7.
Am J Obstet Gynecol ; 222(2): 185.e1-185.e17, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31394068

RESUMO

BACKGROUND: Thalassemia is one of the most common monogenetic diseases in the south of China and Southeast Asia. Hemoglobin Bart's hydrops fetalis syndrome was caused by a homozygous Southeast Asian deletion (-/-) in the HBA gene. Few studies have proved the potential of screen for Bart's hydrops fetalis using fetal cell-free DNA. However, the number of cases is still relatively small. Clinical trials of large samples would be needed. OBJECTIVE: In this study, we aimed to develop a noninvasive method of target-captured sequencing and genotyping by the Bayesian method using cell-free fetal DNA to identify the fetal genotype in pregnant women who are at risk of having hemoglobin Bart hydrops fetalis in a large-scale study. STUDY DESIGN: In total, 192,173 couples from 30 hospitals were enrolled in our study and 878 couples were recruited, among whom both the pregnant women and their husbands were detected to be carriers of Southeast Asian type (-/αα) of α-thalassemia. Prenatal diagnosis was performed by chorionic villus sampling, amniocentesis, or cordocentesis using gap-polymerase chain reaction considered as the golden standard. RESULTS: As a result, we found that the sensitivity and specificity of our noninvasive method were 98.81% and 94.72%, respectively, in the training set as well as 100% and 99.31%, respectively, in the testing set. Moreover, our method could identify all of 885 maternal samples with the Southeast Asian carrier and 36 trisomy samples with 100% of sensitivity in T13, T18, and T21 and 99.89% (1 of 917) and 99.88% (1 of 888) of specificity in T18 and T21, respectively. CONCLUSION: Our method opens the possibility of early screening for maternal genotyping of α-thalassemia, fetal aneuploidies in chromosomes 13/18/21, and hemoglobin Bart hydrops fetalis detection in 1 tube of maternal plasma.


Assuntos
Hemoglobinas Anormais/genética , Hidropisia Fetal/diagnóstico , Amniocentese , Teorema de Bayes , Ácidos Nucleicos Livres , Amostra da Vilosidade Coriônica , Cordocentese , Síndrome de Down/diagnóstico , Feminino , Genótipo , Heterozigoto , Humanos , Hidropisia Fetal/genética , Teste Pré-Natal não Invasivo , Gravidez , Sensibilidade e Especificidade , Síndrome da Trissomia do Cromossomo 13/diagnóstico , Síndrome da Trissomía do Cromossomo 18/diagnóstico , Talassemia alfa/diagnóstico , Talassemia alfa/genética
8.
J Clin Pathol ; 73(5): 278-282, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31653757

RESUMO

AIMS: Thalassemia is one of the most prevalent inherited disorders in south China. However, there still has no comprehensive research on molecular characterisation of α-thalassemia and ß-thalassemia in the Quanzhou region of Fujian province, a city with high incidence of thalassemia in Southeast China. METHODS: A total of 11 668 cases were collected in Quanzhou region from January 2013 to June 2019. The deletions of α-thalassemia were detected by Gap-PCR, α-thalassemia and ß-thalassemia mutations were detected by DNA reverse dot blot hybridisation. Rare thalassemia gene testing and DNA sequencing were performed to detect rare and novel thalassemia mutation for suspected rare thalassemia carriers. RESULTS: Among 11 668 subjects, 4796 (41.10%) subjects were diagnosed with thalassemia. 3298 (28.27%) subjects were α-thalassemia carriers, 26 types of α-thalassemia mutations were identified, with the common α-thalassemia genotypes being --SEA/αα (71.47%), -α3.7/αα (17.13%) and -α4.2/αα (3.49%). 1407 (12.06%) subjects were ß-thalassemia carriers, 18 types of ß-thalassemia mutations were identified. The common five genotypes of ß-thalassemia were ßIVS-II-654/ßN (36.53%), ßCD41-42/ßN (30.28%), ßCD17/ßN (17.13%), ßCD26/ßN (5.12%) and ß-28/ßN (4.62%). Additionally, 91 (0.78%) subjects with composite α-thalassemia and ß-thalassemia were identified. Furthermore, 9 α-thalassemia and ß-thalassemia gene mutations (CAP +40-43 (-AAAC), IVS-I-1 (G>T), IVS-I-5 (G>C), SEA-HPFH, CD53 (-T), CD37 (A>G), -90 (C>T), CD3 (T>C), -α6.9) were identified for the first time in the region. Among them, CD53 (-T), CD37 (A>G) and -90 (C>T) mutations were identified for the first time in Fujian province. Moreover, CD3 (T>C), -α6.9 mutations were first identified in Chinese individual. CONCLUSIONS: Quanzhou region of South China has high incidence of thalassemia mutations. In this study, several cases of rare thalassemia mutations have been identified, providing reference for clinical consultation. The completion of this study is of great significance to strengthen the prevention and control of thalassaemia in the Quanzhou region.


Assuntos
Mutação , Talassemia alfa/genética , Talassemia beta/genética , Adolescente , Adulto , China , Feminino , Marcadores Genéticos , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Análise de Sequência de DNA , Adulto Jovem , Talassemia alfa/diagnóstico , Talassemia alfa/epidemiologia , Talassemia beta/diagnóstico , Talassemia beta/epidemiologia
9.
J Clin Pathol ; 73(1): 14-16, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31434698

RESUMO

AIMS: Untranslated regions (UTRs) play an important role in post-transcriptional regulation of gene expression, including by modulating messenger RNA (mRNA) transport out of the nucleus, translation efficiency, subcellular localisation and stability. Any mutation in this region could alter the stability of mRNA and thereby affect protein synthesis. We analysed if a mutation located in the α complex protected region of the α1 globin gene could cause non-deletional α-thalassaemia by affecting post-transcriptional stability (mRNA stability). METHODS: A total of 14 patients without anaemia, normal or slight microcytosis and hypochromia (medium concentration haemoglobin [MCH] <27 pg) were studied. Haemoglobin subtypes were screened using capillary zone electrophoresis and ion-exchange high-performance liquid chromatography (VARIANT II ß-Thalassaemia Short Program). The most common α-globin mutations were identified by multiplex PCR (Alpha-Globin StripAssay kit) and the molecular characterisation by automatic sequencing of alpha globin genes. RESULTS: All of them shown a novel transversion mutation in nt 778 (C>A), which is located in the 3' UTR in the α complex protected region [HBA1: c.*+46C>A]. CONCLUSIONS: This mutation is in the αRNAmin binding site, so a single nucleotide substitution in this region can decrease mRNA stability by potentially compromising the binding of α-complex protein to αRNAmin, favouring the decay of α-globin mRNA via erythroid cell-enriched endoribonuclease cleavage. In this case, it is a non-deletional α-thalassaemia. However, in silico and empirical studies predicted that it could be a silent polymorphism. Functional studies should be carried out to confirm whether it is a pathological mutation or a silent polymorphism.


Assuntos
Regiões 3' não Traduzidas , Mutação , Polimorfismo Genético , Estabilidade de RNA , RNA Mensageiro/genética , alfa-Globinas/genética , Talassemia alfa/genética , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Análise Mutacional de DNA/métodos , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Fenótipo , RNA Mensageiro/metabolismo , Fatores de Risco , alfa-Globinas/metabolismo , Talassemia alfa/sangue , Talassemia alfa/diagnóstico
10.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(6): 1938-1942, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31839063

RESUMO

OBJECTIVE: To investigate the type and distritution of thalassemia gene mutaitons in Hunan area, so as to provide evidence for prenatal screening, diagnosis and reduction of birth defects. METHODS: A total of 5018 cases from Maternal and Children Health Hospital of Hunan from June 2017 to Dec 2018 were undergone thalassemia gene mutation analysis. The reverse dot blot hydridization was used to detect 6 kinds of genotypes of α-thalassemia and 17 kinds of point mutations of ß-thalassemia, and the detected data were analyzed statistically. RESULTS: 889 cases (55.9%) of α-thalassemia carriers were found, including 385 cases of silent α-thalassemia, 488 cases of α-thalassemia trait, 16 cases of Hb H disease. --SEA/αα was the most common genotype in α thalassemia. 664 cases (41.7%) were diagnosed as ß-thalassemia carriers, heterozygotes accounted for 99.8% (663/664), IVS-Ⅱ-654, CD41-42M and CD17M were the main genotypes, and compound heterozygote accounted for 0.2% (1/664). 38 cases were diagnosed as α-thalassemia combined ß-thalassemia. CONCLUSION: The constituent ratio of thalassemia gene mutations in Hunan has regional characteristics, --SEA/αα is the most common genotype in α-thalassemia carrier. IVS-Ⅱ-654, CD41-42 and CD17 are common ones in ß-thalassemia. The frequency of α-thalassemia combined with ß-thalassemia is high.


Assuntos
Talassemia alfa , Talassemia beta , Criança , China , Feminino , Genótipo , Heterozigoto , Humanos , Mutação , Gravidez , Diagnóstico Pré-Natal , Talassemia alfa/genética , Talassemia beta/genética
11.
Hemoglobin ; 43(4-5): 241-244, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31690131

RESUMO

Although mutations causing α-thalassemia (α-thal) are mainly larger deletions involving one or both of the duplicated α-globin genes, point mutations are not rare. We have identified a novel mutation of the translation initiation codon of the α2-globin gene with DNA sequencing and allele-specific multiplex ligation-dependent probe amplification (MLPA) in a Chinese family. RNA analysis was performed with reverse transcription-MLPA (RT-MLPA). A novel mutation at the translation initiation codon of the α2-globin gene (HBA2: c.3G>C) was identified. The proband and his father, who were both carriers of this mutation, had a hematological phenotype of mild α+-thalassemia (α+-thal) trait with low-normal limit of mean corpuscular volume (MCV) and normal Hb A2. RNA analysis showed markedly decreased levels of α-globin mRNA and the presence of a small amount of mutant mRNA. The HBA2: c.3G>C mutation most likely caused α-thal by lowering levels of wild α-globin chain. Our study increases the mutation spectrum of α-thal.


Assuntos
Códon de Iniciação/genética , Mutação Puntual , alfa-Globinas/genética , Talassemia alfa/genética , Grupo com Ancestrais do Continente Asiático , Sequência de Bases , Índices de Eritrócitos , Família , Feminino , Hemoglobina A2/genética , Hemoglobinas Anormais/genética , Humanos , Masculino , Fenótipo
12.
Hemoglobin ; 43(4-5): 245-248, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31687860

RESUMO

The capillary electrophoresis (CE) system allows the quantification of Hb Bart's (γ4) and Hb H (ß4) that is used for screening of Hb H disease. However, Hb Bart's hydrops fetalis and Hb H are not always codetected in patients with Hb H disease. In this study, 35 samples were analyzed for the α0-thalassemia (α0-thal) [- -SEA (Southeast Asian) and - -THAI (Thailand)] deletions and the α+-thal [-α3.7 (rightward) and -α4.2 (leftward)] type deletions using real time-polymerase chain reaction (real time-PCR) with SYBR Green1 and high-resolution melting (HRM) analysis and conventional gap-PCR techniques, respectively. Results showed that 28 of 29 (96.6%) samples with the Hb A2-Hb H phenotype on CE electrophoregrams presented the genotype of - -SEA/-α3.7, while the - -SEA/-α4.2 made up the remainder. The - -SEA/-α3.7 genotype was also found in all six samples (100.0%) with Hb A2-Hb Bart's on CE electrophoregrams. Thus, for genetic counseling, prevention and control programs of Hb Bart's hydrops fetalis and Hb H disease, α-thal genotype analysis is required.


Assuntos
Eletroforese Capilar/métodos , Hemoglobina A2/genética , Hemoglobina H/genética , Hemoglobinas Anormais/genética , Deleção de Sequência , Feminino , Genótipo , Humanos , Hidropisia Fetal/diagnóstico , Gravidez , Diagnóstico Pré-Natal/métodos , Talassemia alfa/diagnóstico , Talassemia alfa/genética
13.
Int J Mol Sci ; 20(21)2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31671722

RESUMO

Methyl-CpG binding protein 2 (MeCP2) is a multi-function factor involved in locus-specific transcriptional modulation and the regulation of genome architecture, e.g., pericentric heterochromatin (PCH) organization. MECP2 mutations are responsible for Rett syndrome (RTT), a devastating postnatal neurodevelopmental disorder, the pathogenetic mechanisms of which are still unknown. MeCP2, together with Alpha-thalassemia/mental retardation syndrome X-linked protein (ATRX), accumulates at chromocenters, which are repressive PCH domains. As with MECP2, mutations in ATRX cause ATR-X syndrome which is associated with severe intellectual disability. We exploited two murine embryonic stem cell lines, in which the expression of MeCP2 or ATRX is abolished. Through immunostaining, chromatin immunoprecipitation and western blot, we show that MeCP2 and ATRX are reciprocally dependent both for their expression and targeting to chromocenters. Moreover, ATRX plays a role in the accumulation of members of the heterochromatin protein 1 (HP1) family at PCH and, as MeCP2, modulates their expression. Furthermore, ATRX and HP1 targeting to chromocenters depends on an RNA component. 3D-DNA fluorescence in situ hybridization (FISH) highlighted, for the first time, a contribution of ATRX in MeCP2-mediated chromocenter clustering during neural differentiation. Overall, we provide a detailed dissection of the functional interplay between MeCP2 and ATRX in higher-order PCH organization in neurons. Our findings suggest molecular defects common to RTT and ATR-X syndrome, including an alteration in PCH.


Assuntos
Diferenciação Celular/fisiologia , Heterocromatina/metabolismo , Proteína 2 de Ligação a Metil-CpG/metabolismo , Neurônios/metabolismo , Proteína Nuclear Ligada ao X/metabolismo , Animais , Diferenciação Celular/genética , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Modelos Animais de Doenças , Células-Tronco Embrionárias , Regulação da Expressão Gênica , Técnicas de Inativação de Genes , Heterocromatina/química , Heterocromatina/genética , Hibridização in Situ Fluorescente , Deficiência Intelectual/genética , Retardo Mental Ligado ao Cromossomo X/genética , Proteína 2 de Ligação a Metil-CpG/genética , Camundongos , Mutação , Síndrome de Rett/genética , Proteína Nuclear Ligada ao X/química , Proteína Nuclear Ligada ao X/genética , Talassemia alfa/genética
14.
Hemoglobin ; 43(4-5): 286-288, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31650882

RESUMO

Here we report a 67-year-old Chinese male carrying an unstable novel hemoglobin (Hb) variant in compound heterozygosity with the - -SEA (Southeast Asian) α-thalassemia (α-thal) deletion. Hemoglobin analysis by capillary electrophoresis (CE) revealed a rapid degradation feature of the variant. Sanger sequencing of the Hb gene revealed a novel homozygous mutation in exon 2 of the α1-globin gene [α52(E1)Ser→Cys (TCT>TGT); HBA1: c.158C>G]. We named this novel variant Hb Dongguan for the place of origin of the proband. Additionally, gap-polymerase chain reaction (gap-PCR) indicated the presence of the heterozygous - -SEA α-thal deletion.


Assuntos
Hemoglobinas Anormais/genética , Heterozigoto , alfa-Globinas/genética , Talassemia alfa/genética , Idoso , Grupo com Ancestrais do Continente Asiático , Eletroforese Capilar , Homozigoto , Humanos , Masculino , Mutação , Estabilidade Proteica , Deleção de Sequência
15.
Hemoglobin ; 43(4-5): 236-240, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31635494

RESUMO

The α0-thalassemia (α0-thal) [- -SEA (Southeast Asian) deletion] is highly prevalent in Southeast Asia and South China. The linkage between the single nucleotide polymorphism (SNP) rs77308790 and the - -SEA deletion was reported in the Chinese population. This study reported the genotype of SNP rs77308790 using the high resolution melting (HRM) curve analysis in the Thai population and the application for double-checking diagnosis of Hb Bart's (γ4) hydrops fetalis syndrome. A total of 202 samples, including α0-thal carriers (- -SEA/αα) (n = 99) and wild-type (n = 103), was recruited. Minor allele frequency (MAF) of SNP rs77308790 (T allele) represented a significant difference (p<0.001) between carrier (- -SEA deletion) (MAF 0.455) and wild-type (MAF 0.039). The T allele of SNP rs77308790 showed a strong linkage with the - -SEA deletion allele [correlation coefficient between pairs of loci (D' = 1)] based on constructed random samples (CRSs) in Thais. Moreover, worldwide populations, based on the 1000Genomes database, also found the T allele to be less than 1.0%. For providing a double-checked diagnosis, two SNP (rs3760053, rs77308790) genotypes showed 100.0% concordance with a conventional gap-polymerase chain reaction (gap-PCR) method in nine families at-risk for Hb Bart's hydrops fetalis. The double-checked diagnosis based on the two SNPs (rs3760053, rs77308790) is suitable for implementation in routine diagnosis of Hb Bart's hydrops fetalis syndrome. Furthermore, our HRM analysis system can be amplified with a small amount of fetal DNA and could avoid allele dropouts.


Assuntos
Ligação Genética , Hidropisia Fetal/diagnóstico , Polimorfismo de Nucleotídeo Único , Diagnóstico Pré-Natal/métodos , Deleção de Sequência , Talassemia alfa/genética , Alelos , Família , Feminino , Hemoglobinas Anormais/genética , Humanos , Masculino , Gravidez , Tailândia
16.
Hemoglobin ; 43(4-5): 249-253, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31581858

RESUMO

This study assessed thalassemia and hemoglobinopathies in a group of the Tay ethnic minority. Participants included 289 women of reproductive-age who enrolled in a pilot screening program for thalassemia conducted at six communities of Thai Nguyen Province, northern Vietnam. Standard procedures including complete blood count (CBC), hemoglobin (Hb) and DNA analyses were performed for all samples. The prevalence of thalassemia in 289 Tay women was 15.6% (gene frequency 0.078) for α0-thalassemia (α0-thal), 10.0% (gene frequency 0.050) for α+-thal, 7.3% (gene frequency 0.036) for ß-thalassemia (ß-thal), 2.4% (gene frequency 0.012) for Hb Constant Spring [Hb CS; α142, Term→Gln, TAA>CAA (α2), HBA2: c.427T>C] and 1.7% (gene frequency 0.009) for Hb E [ß26(B8)Glu→Lys, GAG>AAG; HBB: c.79G>A]. Further analysis of ß-globin gene abnormalities identified four mutations including codons 41/42 (-TCTT) (HBB: c.126_129delCTTT), codon 17 (A>T) (HBB: c.52A>T), codons 71/72 (+A) (HBB: c.216_217insA), and -28 (A>G) (HBB: c.78A>G). The results hint at the remarkably high frequencies of severe forms of thalassemia that indicate a serious public health problem requiring further exploration, and most probably, also intervention within the country.


Assuntos
Hemoglobinopatias/etnologia , Grupos Minoritários , Talassemia/etnologia , Grupos Étnicos , Feminino , Frequência do Gene , Hemoglobinopatias/genética , Hemoglobinas Anormais , Humanos , Programas de Rastreamento , Mutação , Prevalência , Talassemia/genética , Vietnã/epidemiologia , Vietnã/etnologia , Talassemia alfa/etnologia , Talassemia alfa/genética , Globinas beta/genética , Talassemia beta/etnologia , Talassemia beta/genética
17.
Ann Hematol ; 98(12): 2661-2671, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31495903

RESUMO

Haemoglobin (Hb) H-constant spring (CS) alpha thalassaemia (- -/-αCS) is the most common type of nondeletional Hb H disease in southern China. The CRISPR/Cas9-based gene correction of patient-specific induced pluripotent stem cells (iPSCs) and cell transplantation now represent a therapeutic solution for this genetic disease. We designed primers for the target sites using CRISPR/Cas9 to specifically edit the HBA2 gene with an Hb-CS mutation. After applying a correction-specific PCR assay to purify the corrected clones followed by sequencing to confirm the mutation correction, we verified that the purified clones retained full pluripotency and exhibited a normal karyotype. This strategy may be promising in the future, although it is far from representing a solution for the treatment of HbH-CS thalassemia now.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Hemoglobinas Anormais , Células-Tronco Pluripotentes Induzidas/metabolismo , Talassemia alfa , Hemoglobinas Anormais/genética , Hemoglobinas Anormais/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Talassemia alfa/genética , Talassemia alfa/metabolismo , Talassemia alfa/terapia
18.
Hemoglobin ; 43(2): 107-111, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31304855

RESUMO

α-Thalassemia (α-thal) is one of the most common genetic disorders worldwide. The aim of this study was to investigate for the first time the α-thal mutation spectrum in the Lak population living in Lorestan Province, Iran. One hundred and seventy-six α-thal carriers participated in the study. Multiplex gap-polymerase chain reaction (gap-PCR), amplification refractory mutation system (ARMS)-PCR and direct sequencing were used for the detection of different mutations on the α-globin (HBA1 and HBA2) genes. A total of 11 different mutations was identified. The -α3.7 (rightward; NG_000006.1: g.34164_37967del3804) deletion was observed most frequently (56.35%), followed by α-5 ntα (HBA2: c.95+2_95+6delTGAGG), αpolyA2α (HBA2: c.*92A>G) and - -MED I (NG_000006.1: g.24664_41064del16401), with frequencies of 15.47, 9.39, and 6.08%, respectively. These four mutations accounted for more than 87.0% of the total mutated alleles. Moreover, 19 different genotypes were identified. The types and distribution pattern of the mutations identified in this study, in comparison with other studies conducted in Iran, was most similar to the Kurdish population of Kermanshah Province, Iran. Due to the lack of information on α-thal in Lorestan Province, it was not possible to compare the mutation spectrum in the Lur and Lak populations. In conclusion, our results may help in setting up a strategy for an α-thal screening program and genetic counseling in the Lak people.


Assuntos
Mutação , alfa-Globinas/genética , Talassemia alfa/genética , Genótipo , Heterozigoto , Humanos , Irã (Geográfico)/epidemiologia , Irã (Geográfico)/etnologia , Análise de Sequência de DNA/métodos , Talassemia alfa/etnologia
19.
Int J Lab Hematol ; 41(5): 650-656, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31271507

RESUMO

INTRODUCTION: Thalassemias and hemoglobinopathies are the most prevalent inherited anemias detected in South East Asians. These disorders represent not only a clinical health problem but also a socioeconomic problem for this region. Regarding the prevention and control of thalassemias and hemoglobinopathies in the Lao PDR, screening and diagnostic strategies should be strongly considered. The knowledge about the prevalence and molecular genotyping of thalassemias and hemoglobinopathies among the Lao Loum group, which includes the majority of Lao people, is now limited, making the prevention and control of thalassemias difficult. METHODS: This study aimed to determine the prevalence of thalassemia among Lao Loum subjects of reproductive age. Multiplex gap PCR and direct sequencing were used to investigate the mutations of α-globin and ß-globin genes. RESULTS: Thalassemias and hemoglobinopathies were detected in 154 of 354 (43.50%) patients, and 22 different genotypes were identified in this cohort. Remarkably, high frequencies of hemoglobin E, α0 -thalassemia (--SEA ), and α+ -thalassemia (-α3.7 ) were noted. A variety of hematologic features was observed, including co-inheritance of heterozygous HbE and heterozygous α-thalassemia, which was associated with significantly lower levels of MCV and MCH values than those observed in typical HbE heterozygotes. Female participants who were heterozygous for ß0 or co-inheritance of heterozygous ßE with heterozygous α-thalassemia exhibited mild anemia. CONCLUSION: Our data show that thalassemias and hemoglobinopathies have become health problems imposing a serious burden in the Lao PDR. Prevention programs aimed at decreasing the incidence of severe thalassemia diseases should be designed and initiated.


Assuntos
Hemoglobina E/genética , Hemoglobinopatias/genética , Mutação , alfa-Globinas/genética , Talassemia alfa/genética , Talassemia beta/genética , Adolescente , Feminino , Frequência do Gene , Testes Genéticos/métodos , Genótipo , Hemoglobinopatias/diagnóstico , Hemoglobinopatias/epidemiologia , Humanos , Laos/epidemiologia , Masculino , Prevalência , Adulto Jovem , Talassemia alfa/diagnóstico , Talassemia alfa/epidemiologia , Talassemia beta/diagnóstico , Talassemia beta/epidemiologia
20.
Mol Biol Rep ; 46(5): 5041-5048, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31273613

RESUMO

Thalassemia is one of the most common monogenic hereditary disorders. Despite noticeable advances made in prevention strategies, it is still highly prevalent in the Iranian population. A key approach to management and early diagnosis of the disease is through revealing the regions with high prevalence and determining common genetic and phenotypic diversity. In the current study Hemoglobin H (HbH) disease patients were analyzed as the most common form of thalassemia intermedia in Iran. A total of 80 patients suspected of being thalassemic according to their mild to moderate anemia, microcytosis and normal iron levels were included in this study at the hemoglobinopathy and thalassemia center of Ahvaz University of Medical Science. Patients were analyzed for hematological parameters and HbH mutations using Multiplex Gap Polymerase Chain Reaction and Multiplex Amplification Refractory Mutation System. Twelve mutations were detected in the studied population. The most common genotype was -α3.7/--MED (45%) followed by Homozygote αPoly A2 (17.5%). A total of ten different alpha-globin (α-globin) mutations were observed in patients which --MED, being the most common mutation (26.27%), followed by -α3.7 (24.37%) and αpolyA2(A>G) (18.12%). Hematological parameters such as Hb, MCV, MCH and HbH were assessed and results showed that they varied significantly among genotypes, adjusted to age and gender. This study reveals a highly diverse range of HbH patients different from what was thought in terms of both genotype and phenotype in the Khuzestan region of Iran. These findings could contribute to improve the thalassemia managing policies in this province.


Assuntos
Talassemia/genética , Talassemia alfa/genética , Adolescente , Adulto , Feminino , Estudos de Associação Genética/métodos , Genótipo , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Mutação , Fenótipo , Talassemia/metabolismo , Adulto Jovem , alfa-Globinas/genética , alfa-Globinas/metabolismo , Talassemia alfa/metabolismo , Talassemia beta/genética
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