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1.
Br J Haematol ; 204(6): 2184-2193, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38578212

RESUMO

Sickle cell disease (SCD) arises from beta-globin gene mutations, with global estimates indicating around 500 000 affected neonates in 2021. In the United States, it is considered rare, impacting fewer than 200 000 individuals. The key pathogenic flaw lies in mutant haemoglobin S, prone to polymerization under low oxygen conditions, causing erythrocytes to adopt a sickled shape. This leads to complications like vascular occlusion, haemolytic anaemia, inflammation and organ damage. Beyond erythrocyte abnormalities however, there is a body of literature highlighting the hypercoagulable state that is likely a contributor to many of the complications we see in SCD. The persistent activation of the coagulation cascade results in thromboembolic events, notably venous thromboembolism (VTE) which is independently associated with increased mortality in both adults and children with SCD. While the increased risk of VTE in the SCD population seems well established, there is a lack of guidelines for thromboprophylaxis in this population. This Wider Perspective will describe the hypercoagulable state and increased thrombosis risk in the SCD population, as well as advocate for the development of evidence-based guidelines to aid in the prevention of VTE in SCD.


Assuntos
Anemia Falciforme , Tromboembolia Venosa , Anemia Falciforme/complicações , Humanos , Tromboembolia Venosa/prevenção & controle , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/epidemiologia , Anticoagulantes/uso terapêutico , Lacunas de Evidências
2.
Biochem Genet ; 62(2): 666-674, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37395849

RESUMO

Short tandem repeats located 5' prime to the ß-globin gene, have been observed to be in linkage disequilibrium with the HbS allele, and thought to affect the severity of sickle cell disease. Here, we report on new mutants within the HBG2 region that may impact sickle cell disease. To determine the cis-acting elements microsatellites, indels and single nucleotide polymorphisms (SNPs), within the HBG2 region by sequencing, in subjects with sickle cell disease. The case-control study was located at the Center for Clinical Genetics, Sickle cell unit, Korle-Bu Teaching Hospital. A questionnaire was used for demographic data and clinical information. Hematological profile (red blood cell, white blood cell, platelet, hemoglobin and mean corpuscular volume) were assessed in 83 subjects. A set of 45 samples comprising amplified DNA on the HBG2 gene from HbSS (22), HbSC (17) and 6 controls (HbAA) were sequenced. Differences in the microsatellite region between sickle cell disease (SCD) (HbSS and HbSC) genotypes and control subjects were identified by counting and assessed by Chi-square analysis. Red blood cells, hematocrit, platelets, white blood cells and hemoglobin indices differed in genotypic groups. HbSS subjects were affirmed to have severer hemolytic anemia than HbSC subjects. Two indels (T1824 and C905) were seen in both SS and SC genotypes. Two peculiar SNPs: G:T1860 (transition) and A:G1872 transversions were found within the HBG2 gene that were significantly associated with the HbSS genotype (Fisher's exact test, p = 0.006) and HbS allele respectively (Fisher's exact test, p = 0.006). Cis-acting elements in HbSS and HbSC were different and may contribute to the phenotype seen in the disease state.

3.
Hemoglobin ; 48(3): 209-211, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-39103306

RESUMO

Hemoglobin Strasbourg is a rare high oxygen affinity hemoglobin variant which leads to secondary erythrocytosis. This variant is caused by a HBB gene mutation c.71T > A resulting in an amino acid exchange on position 23 of the ß globin chain (p.Val23Asp.). The influence of Hb Strasbourg on HbA1c measurement has not been studied to date. For patients with hemoglobin variants it is important to know whether possible interferences exist with the measurement of HbA1c. We therefore investigated the influence of Hb Strasbourg on HbA1c measurement with two different HPLC (high-performance liquid chromatography) systems and one turbidimetric immunoassay in two non-diabetic brothers who are heterozygous carriers of Hb Strasbourg. The examined tests are all used in routine diagnostics. In the case of Hb Strasbourg, the HbA1c measured by HPLC showed lower results than those obtained by the immunoassay. We conclude that HbA1c is underestimated when measured with these methods as glycated Hb Strasbourg is most likely not co-eluting with HbA1c in HPLC.


Assuntos
Hemoglobinas Glicadas , Hemoglobinas Anormais , Humanos , Hemoglobinas Glicadas/análise , Hemoglobinas Anormais/genética , Cromatografia Líquida de Alta Pressão , Masculino , Imunoensaio/métodos , Oxigênio/metabolismo , Nefelometria e Turbidimetria
4.
Hemoglobin ; : 1-4, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38961566

RESUMO

We report the discovery of a novel ß-globin gene variant, Hb Odder, characterized by a single nucleotide substitution; HBB:c.316C > G; CD105 (Leu > Val). This variant emerged incidentally during routine HbA1c measurements for diabetes monitoring. The patient exhibited no clinical or biochemical evidence of anemia or hemolysis. Our data on this variant suggest that Hb Odder is benign, regrettably limitations in our data make formal evaluations of stability and oxygen affinity impossible; additionally this emphasizes the importance of considering hemoglobin variants in the differential diagnosis of abnormal Hb A1c levels and suggest that laboratories should use alternative methods for the correct measurement of Hb A1c when hemoglobin variants interfere with diabetes monitoring. Notably, three other mutations have been described at codon 105 of the ß globin chains and correspond to three Hb variants with different characteristics: Hb South Milwaukee, Hb Bellevue IV and Hb St. George.

5.
Mol Ther ; 30(6): 2199-2209, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35247584

RESUMO

The globin genes are archetypal tissue-specific genes that are silent in most tissues but for late-stage erythroblasts upon terminal erythroid differentiation. The transcriptional activation of the ß-globin gene is under the control of proximal and distal regulatory elements located on chromosome 11p15.4, including the ß-globin locus control region (LCR). The incorporation of selected LCR elements in lentiviral vectors encoding ß and ß-like globin genes has enabled successful genetic treatment of the ß-thalassemias and sickle cell disease. However, recent occurrences of benign clonal expansions in thalassemic patients and myelodysplastic syndrome in patients with sickle cell disease call attention to the non-erythroid functions of these powerful vectors. Here we demonstrate that lentivirally encoded LCR elements, in particular HS1 and HS2, can be activated in early hematopoietic cells including hematopoietic stem cells and myeloid progenitors. This activity is position-dependent and results in the transcriptional activation of a nearby reporter gene in these progenitor cell populations. We further show that flanking a globin vector with an insulator can effectively restrain this non-erythroid activity without impairing therapeutic globin expression. Globin lentiviral vectors harboring powerful LCR HS elements may thus expose to the risk of trans-activating cancer-related genes, which can be mitigated by a suitable insulator.


Assuntos
Anemia Falciforme , Globinas , Anemia Falciforme/genética , Terapia Genética/métodos , Vetores Genéticos/genética , Globinas/genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , Globinas beta/genética , Globinas beta/metabolismo
6.
Molecules ; 27(15)2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35897939

RESUMO

Deer antler is a globally widely used precious natural medicine and the material of deer horn gelatin. However, identification of deer antler species based on traditional approaches are problematic because of their similarity in appearance and physical-chemical properties. In this study, we performed a comprehensive antler peptidome analysis using a label-free approach: nano LC-Orbitrap MS was applied to discover peptide biomarkers in deer adult beta-globin (HBBA), and HPLC-Triple Quadrupole MS was used to verify their specificity. Nineteen peptide biomarkers were found, on which foundation a strategy for antlers and a strategy for antler mixtures such as flakes or powder are provided to identify seven species of deer antler including Eurasian elk (Alces alces), reindeer (Rangifer tarandus), white-tailed deer (Odocoileus viginianus), white-lipped deer (Przewalskium albirostris), fallow deer (Dama dama), sika deer (Cervus nippon), and red deer (Cervus elaphus) simultaneously. It is worth noting that our search found that the HBBA gene of sika deer, red deer, and North American wapiti (Cervus canadensis) in China may have undergone severe genetic drifts.


Assuntos
Chifres de Veado , Cervos , Animais , Chifres de Veado/química , Cromatografia Líquida , Cervos/genética , Peptídeos/análise , Espectrometria de Massas em Tandem
7.
Blood Cells Mol Dis ; 70: 66-77, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28689691

RESUMO

The single base molecular substitution characterizing sickle cell haemoglobin, ß6glu→val, might be expected to result in predictable haematological and clinical features. However, the disease manifests remarkable diversity believed to reflect the interaction with other genetic and environmental factors. Some of the genetic modifiers include the beta globin haplotypes, alpha thalassaemia, factors influencing the persistence of fetal haemoglobin and the effects of the environment are addressed in this review. It is concluded that much of the genetic data present conflicting results. Environmental factors such as climate and infections, and psychological, educational and social support mechanisms also influence expression of the disease. These interactions illustrate how the expression of a 'single gene' disorder may be influenced by a variety of other genetic and environmental factors.


Assuntos
Anemia Falciforme/genética , Hemoglobina Falciforme/genética , Homozigoto , Mutação , Alelos , Anemia Falciforme/diagnóstico , Anemia Falciforme/epidemiologia , Animais , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Haplótipos , Hemoglobina Falciforme/metabolismo , Humanos , Padrões de Herança , alfa-Globinas/genética , Globinas beta/genética
8.
BMC Genet ; 19(1): 1, 2018 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-29295702

RESUMO

BACKGROUND: Bangladesh lies in the global thalassemia belt, which has a defined mutational hot-spot in the beta-globin gene. The high carrier frequencies of beta-thalassemia trait and hemoglobin E-trait in Bangladesh necessitate a reliable DNA-based carrier screening approach that could supplement the use of hematological and electrophoretic indices to overcome the barriers of carrier screening. With this view in mind, the study aimed to establish a high resolution melting (HRM) curve-based rapid and reliable mutation screening method targeting the mutational hot-spot of South Asian and Southeast Asian countries that encompasses exon-1 (c.1 - c.92), intron-1 (c.92 + 1 - c.92 + 130) and a portion of exon-2 (c.93 - c.217) of the HBB gene which harbors more than 95% of mutant alleles responsible for beta-thalassemia in Bangladesh. RESULTS: Our HRM approach could successfully differentiate ten beta-globin gene mutations, namely c.79G > A, c.92 + 5G > C, c.126_129delCTTT, c.27_28insG, c.46delT, c.47G > A, c.92G > C, c.92 + 130G > C, c.126delC and c.135delC in heterozygous states from the wild type alleles, implying the significance of the approach for carrier screening as the first three of these mutations account for ~85% of total mutant alleles in Bangladesh. Moreover, different combinations of compound heterozygous mutations were found to generate melt curves that were distinct from the wild type alleles and from one another. Based on the findings, sixteen reference samples were run in parallel to 41 unknown specimens to perform direct genotyping of the beta-thalassemia specimens using HRM. The HRM-based genotyping of the unknown specimens showed 100% consistency with the sequencing result. CONCLUSIONS: Targeting the mutational hot-spot, the HRM approach could be successfully applied for screening of beta-thalassemia carriers in Bangladesh as well as in other countries of South Asia and Southeast Asia. The approach could be a useful supplement of hematological and electrophortic indices in order to avoid false positive and false negative results.


Assuntos
Triagem de Portadores Genéticos/métodos , Hibridização de Ácido Nucleico/métodos , Globinas beta/genética , Talassemia beta/diagnóstico , Adolescente , Bangladesh , Criança , Pré-Escolar , Triagem de Portadores Genéticos/economia , Hemoglobina E/genética , Humanos , Lactente , Mutação , Talassemia beta/genética
9.
Ann Hematol ; 97(5): 893-898, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29453624

RESUMO

The haematological and clinical response to hydroxyurea was estimated in HbE-beta, beta thalassaemia and sickle cell anaemia patients of Eastern India, with variable clinical severity and transfusion requirement to determine whether hydroxyurea can help these patients to maintain their steady haemoglobin level without blood transfusions. Three hundred patients (189 HbE-beta thalassaemia, 95 beta thalassaemia and 16 other haemoglobinopathies including sickle cell anaemia) were selected for hydroxyurea therapy and were followed up for 48-60 months. Results suggest significant response to hydroxyurea therapy in 19 beta and 99 HbE-beta patients in the transfusion-dependent group (GR-I). All of them became transfusion-independent while on hydroxyurea therapy. The majority of responding patients were IVS1-5(G-C) in one of their alleles in HbE-beta cases (83 out of 119). Though IVS1-5(G-C) was found to be the commonest mutation in our selected patients, the mutational background of the patients does not found to have any significant correlation with the response category towards hydroxyurea as per the results observed in our study. But, the drug works pretty well in most of the transfusion-dependent patients, as these patients were withdrawn from regular blood transfusion. At the same time, partial or no response to the drug hydroxyurea was also recorded in our study.


Assuntos
Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/epidemiologia , Hidroxiureia/uso terapêutico , Talassemia beta/tratamento farmacológico , Talassemia beta/epidemiologia , Adolescente , Adulto , Anemia Falciforme/diagnóstico , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Índia/epidemiologia , Lactente , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem , Talassemia beta/diagnóstico
10.
J Biomed Sci ; 24(1): 92, 2017 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-29202846

RESUMO

BACKGROUND: Beta-thalassemia is common in the Mediterranean area as well as the Middle East and India. Official report in Iran revealed the average prevalence rate of carriers about 4%. More than 20 restriction fragment length polymorphisms (RFLPs) are known in the beta-globin gene cluster and used in the prenatal diagnosis (PND) services. Some of these locations may have low allele frequency and are not informative in the prenatal diagnosis. The current study aims to find new haplotypes and polymorphisms with high allele frequency in the local population. METHODS: Two thousand three hundred fifty samples (1,321 male and 1,029 female) from the northern Iran, whom suspected to be the carriers either for alpha or beta thalassemia and referred to the local diagnostic laboratory as a routine services were investigated during five years, (2010-2015). The beta-globin gene was sequenced for all samples. RESULTS: Heterozygosity for five SNPs in the beta-globin gene was calculated separately. 383 individuals (16.29%) showed no sign of nucleotide change in the beta-globin gene sequence. In total, codon2 (C/T) 31.72%, IVSII-16 (C/G) 31.72%, IVSII-74 (G/T) 54.71%, IVSII-81 (C/T) 19.47%, and IVSII-666 (T/C) 31.72% were seen respectively. Although all five polymorphisms showed reasonably high heterozygosity, IVSII-74 (G/T) [GG wild type (36.5%), G/T (54.71%) and TT (8.8%)] revealed the highest heterozygosity rate. Four combinations of these five SNPs were defined as new haplotypes named M1 to M4. ARMS-PCR also were designed and applied to detect IVSII-74 (G/T) nucleotide position. CONCLUSIONS: This study represents an intragenic polymorphism, IVSII-74, a reliable position with high heterozygosity rates in Iranian population for PND analysis. TRIAL REGISTRATION: Retrospectively registered.


Assuntos
Ligação Genética , Haplótipos , Polimorfismo Genético , Diagnóstico Pré-Natal/métodos , Globinas beta/genética , Talassemia beta/diagnóstico , Biomarcadores/sangue , Estudos Transversais , Feminino , Frequência do Gene , Humanos , Irã (Geográfico) , Masculino , Gravidez , Talassemia beta/genética
11.
Cell Mol Biol (Noisy-le-grand) ; 63(12): 22-24, 2017 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-29307336

RESUMO

Thalassemia is the most common hereditary haemolytic anemia in Southeast Asia, in which Indonesia is among countries that are at a high risk for thalassemia. It has been reported that mutation in the beta-globin gene is responsible in severe Thalassemia. However, the spectrum of beta-globin gene mutations in Indonesian population varies in different regions . Thus, this study aimed to identify the most prevalent mutation of Thalassemia patients from the Hasan Sadikin Hospital, Bandung, using this as a reference hospital for Thalassemia in West Java. The three most prevalent mutations of beta globin (IVS1nt5, Cd26 (HbE), and IVS1nt1), were conducted in the beginning of this study. Mutations of 291 samples were detected by PCR-RFLP in the Molecular Genetic Laboratory, Faculty of Medicine Universitas Padjadjaran, Bandung. The prevalence of the beta globin gene mutation types were 47.4% IVS1nt5 homozygote, 9.9% compound heterozygote IVS1nt5/HbE, 5.4% compound heterozygote IVS1nt5/IVS1nt1, 1.4% compound heterozygote HbE/IVS1nt1, 1% HbE homozygote, 14.4% Compound heterzygote IVS1nt5/… (no paired mutation), 2.06% compound heterozygote HbE/… (no paired mutation), 1.3% compound heterozygote IVS1nt1/… (no paired mutation), and 7 samples were unidentified. The thalassemia mutation IVS1nt5 homozygote is the most common mutation found in Thalassemia patients at Hasan Sadikin Hospital, Bandung. The samples with unidentified results might carry mutations other than the three that are observed in the present study.


Assuntos
Mutação , Talassemia/genética , Globinas beta/genética , Homozigoto , Hospitais , Humanos , Indonésia
12.
Am J Phys Anthropol ; 164(2): 362-370, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28681914

RESUMO

OBJECTIVES: The island of Sardinia has one of the highest incidence rates of ß-thalassemia in Europe due to its long history of endemic malaria, which, according to historical records, was introduced around 2,600 years ago by the Punics and only became endemic around the Middle Ages. In particular, the cod39 mutation is responsible for more than 95% of all ß-thalassemia cases observed on the island. Debates surround the origin of the mutation. Some argue that its presence in the Western Mediterranean reflects the migration of people away from Sardinia, others that it reflects the colonization of the island by the Punics who might have carried the disease allele. The aim of this study was to investigate ß-globin mutations, including cod39, using ancient DNA (aDNA) analysis, to better understand the history and origin of ß-thalassemia and malaria in Sardinia. MATERIALS AND METHODS: PCR analysis followed by sequencing were used to investigate the presence of ß-thalassemia mutations in 19 individuals from three different Roman and Punic necropolises in Sardinia. RESULTS: The cod39 mutation was identified in one male individual buried in a necropolis from the Punic/Roman period. Further analyses have shown that his mitochondrial DNA (mtDNA) and Y-chromosome haplogroups were U5a and I2a1a1, respectively, indicating the individual was probably of Sardinian origin. CONCLUSIONS: This is the earliest documented case of ß-thalassemia in Sardinia to date. The presence of such a pathogenic mutation and its persistence until present day indicates that malaria was likely endemic on the island by the Roman period, earlier than the historical sources suggest.


Assuntos
Globinas beta/genética , Talassemia beta/genética , Talassemia beta/história , Antropologia Física , Cromossomos Humanos Y/genética , DNA Mitocondrial/análise , DNA Mitocondrial/genética , Doenças Endêmicas/história , Feminino , Haplótipos/genética , História Antiga , Humanos , Itália , Malária/história , Masculino , Mutação/genética
13.
Adv Exp Med Biol ; 1013: 1-26, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29127675

RESUMO

Sickle cell disease (SCD) and ß-thalassemia are among the most common inherited diseases, affecting millions of persons globally. It is estimated that 5-7% of the world's population is a carrier of a significant hemoglobin variant. Without early diagnosis followed by initiation of preventative and therapeutic care, both SCD and ß-thalassemia result in significant morbidity and early mortality. Despite great strides in the understanding of the molecular basis and pathophysiology of these conditions, the burden of disease remains high, particularly in limited resource settings. Current therapy relies heavily upon the availability and safety of erythrocyte transfusions to treat acute and chronic complications of these conditions, but frequent transfusions results in significant iron overload, as well as challenges from acquired infections and alloimmunization. Hydroxyurea is a highly effective treatment for SCD but less so for ß-thalassemia, and does not represent curative therapy. As technology and use of cellular and gene therapies expand, SCD and thalassemia should be among the highest disease priorities.


Assuntos
Anemia Falciforme/terapia , Talassemia beta/terapia , Anemia Falciforme/genética , Anemia Falciforme/fisiopatologia , Antidrepanocíticos/uso terapêutico , Transfusão de Eritrócitos/métodos , Terapia Genética/métodos , Humanos , Hidroxiureia/uso terapêutico , Talassemia beta/genética , Talassemia beta/fisiopatologia
14.
Ann Hum Biol ; 44(8): 747-750, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29047316

RESUMO

Haemoglobin (Hb) E is the most common Hb variant in Asia where its gene frequency approaches 0.3 in some areas. We studied genetic background of Hb E genes among Southeast Asian populations. This study examined ß-globin gene haplotypes linked to haemoglobin E (Hb E) in diverse groups of Southeast Asian populations. The study was conducted on southern Thai (22 alleles), Cambodian (84 alleles), Laotian (120 alleles), Vietnamese (87 alleles) and Burmese (one allele) subjects. Results were compared with those of previous studies in northeast Thailand, the Yunnan of China, West India and Europe. Ten different haplotypes were observed. The four most common haplotypes were haplotypes 1 (- + - + + + -) and 2 (+ - - - - + -) on chromosomes with framework 2 and haplotypes 6 (- + - + + - +) and 7 (+ - - - - - +) on chromosomes with framework 3 variety. Phylogenetic analysis indicated that haplotype 1 is a relatively recent haplotype found in all populations, whereas haplotype 6 is found predominately in Cambodians. The results indicate that at least two genetic origins of Hb E are responsible for the high prevalence and spread of Hb E among Southeast Asian populations.


Assuntos
Alelos , Haplótipos , Hemoglobina E/genética , Sudeste Asiático , Humanos , Filogenia
15.
Eur J Haematol ; 94(6): 498-503, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25284604

RESUMO

We describe here the molecular and hematological characteristics of novel frameshift mutations in exon 2 of the HBB gene (in heterozygous state) found in two Argentinean pediatric patients with dominant ß-thalassemia-like features. In Hb Wilde, HBB:c.270_273delTGAG(p.Glu90Cysfs*67), we detected the deletion of the third base of the codon 89 (T) and the codon 90 (GAG), whereas in Hb Patagonia, HBB:c.296_297dupGT(p.Asp99Trpfs*59), the frameshift mutation was due to a duplication of a 'GT' dinucleotide after the second base of codon 98 (GTG). The Hb Patagonia and Hb Wilde mutations would result in elongated ß-globin chains with modified C-terminal sequences and a total of 155 and 157 amino acids residues, respectively. Based on bioinformatics and structural analysis, as well as protein modeling, we predict that the elongated ß-globins would affect the formation of the αß dimers and their stability, which would further support the mechanism for the observed clinical features in both patients.


Assuntos
Variação Genética , Hemoglobinas Anormais/genética , Globinas beta/genética , Talassemia beta/diagnóstico , Talassemia beta/genética , Adolescente , Adulto , Contagem de Células Sanguíneas , Pré-Escolar , Códon , Análise Mutacional de DNA , Índices de Eritrócitos , Éxons , Feminino , Mutação da Fase de Leitura , Hemoglobinas Anormais/química , Humanos , Masculino , Modelos Moleculares , Polimorfismo de Nucleotídeo Único , Conformação Proteica , Multimerização Proteica , Globinas beta/química
16.
Genet Mol Biol ; 36(3): 316-22, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24130436

RESUMO

Hemoglobinopathies are the most common recessive diseases worldwide but their prevalence in Uruguay has not been investigated. In this study, 397 unrelated outpatient children from the Pereira Rosell Hospital Center (CHPR), as well as 31 selected patients with microcytic anemia and 28 ß-thalassemia carriers were analyzed for hemoglobinopathies by using biochemical and molecular biology methods. Parametric and non-parametric methods were used to compare the hematological indices between groups of genotypes. Of the 397 patients in the first group, approximately 1% (0.76% HbS and 0.25% ß-thalassemia) had a mutation in the HBB gene and 3.3% had ß-thalassemia. These mutations had a heterogeneous distribution that varied according to individual ancestry. HbS was found exclusively in individuals with declared African ancestry and had a carrier frequency of 2.2%. The frequency of α-thalassemia carriers in outpatients of European and African ancestry was 1.2% and 6.5%, respectively. In contrast, the frequency of α-thalassemia carriers in patients with microcytic anemia was 25.8%, significantly higher (p < 0.01) than that observed in the sample as a whole and in Afro-descendants and Euro-descendants. Significant differences were observed in the hematological parameters between individuals with thalassemia genotypes and those with a normal genotype. These results indicate that hemoglobinopathies are a relevant health problem in Uruguay.

17.
Front Genome Ed ; 4: 1085111, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36605051

RESUMO

Sickle cell anaemia (SCA) is one of the common autosomal recessive monogenic disorders, caused by a transverse point mutation (GAG > GTG) at the sixth codon of the beta-globin gene, which results in haemolytic anaemia due to the fragile RBCs. Recent progress in genome editing has gained attention for the therapeutic cure for SCA. Direct correction of SCA mutation by homology-directed repair relies on a double-strand break (DSB) at the target site and carries the risk of generating beta-thalassaemic mutations if the editing is not error-free. On the other hand, base editors cannot correct the pathogenic SCA mutation resulting from A > T base transversion. Prime editor (PE), the recently described CRISPR/Cas 9 based gene editing tool that enables precise gene manipulations without DSB and unintended nucleotide changes, is a viable approach for the treatment of SCA. However, the major limitation with the use of prime editing is the lower efficiency especially in human erythroid cell lines and primary cells. To overcome these limitations, we developed a modular lenti-viral based prime editor system and demonstrated its use for the precise modelling of SCA mutation and its subsequent correction in human erythroid cell lines. We achieved highly efficient installation of SCA mutation (up to 72%) and its subsequent correction in human erythroid cells. For the first time, we demonstrated the functional restoration of adult haemoglobin without any unintended nucleotide changes or indel formations using the PE2 system. We also validated that the off-target effects mediated by the PE2 system is very minimal even with very efficient on-target conversion, making it a safe therapeutic option. Taken together, the modular lenti-viral prime editor system developed in this study not only expands the range of cell lines targetable by prime editor but also improves the efficiency considerably, enabling the use of prime editor for myriad molecular, genetic, and translational studies.

18.
Clin Chim Acta ; 529: 10-16, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35150653

RESUMO

BACKGROUND: Thalassemia is a common inherited haemoglobin disorder worldwide, several methods have been utilized in the step-wise screening. Even though hundreds of mutations in globin genes have been reported, novel mutations are continuously emerging as the development of DNA sequencing. METHODS: The case is a 27-year-old female with abnormal values of routine hematological indices, who was admitted for genetic screening of thalassemia. Genomic DNA was extracted and used for genetic assays cover 26 mutations in HBA and HBB genes: gap-PCR and agarose gel electrophoresis were performed to detect deletions, while PCR-reverse dot blot was used to detect point mutations. The next- and third- generation sequencing were used to identify the known and potential novel genotypes of thalassemia, and multiplex ligation-dependent probe amplification (MLPA) was used for genotype validation. RESULTS: Hematological results indicate microcytic hypochromic anemia, high HbA2 (7.2%) and high HbF (6.2%). None of the known genotypes of thalassemia were matched for this case, but a novel 4.9 Kb deletion at HBB gene (hg38, Chr11: 5226187-5231089) was discovered by the third-generation sequencing, the novel deletion was also validated by MLPA (8 probes, 11p15.4: 203314-207652). CONCLUSIONS: This study suggests the third-generation sequencing has promising potentiality to discover novel genotypes (especially deletions) of thalassemia.


Assuntos
Talassemia alfa , Talassemia beta , Adulto , China , Feminino , Deleção de Genes , Humanos , Análise de Sequência de DNA , Talassemia alfa/genética , Globinas beta/genética , Talassemia beta/diagnóstico
19.
Expert Rev Hematol ; 15(2): 107-116, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35143361

RESUMO

INTRODUCTION: The hematological and clinical features vary markedly between the different genotypes of sickle cell disease. Even within the single genotype of homozygous sickle cell disease (HbSS), there is marked variability that is presumed to result from interacting genetic and environmental factors. AREAS COVERED: The classification of the different genotypes of sickle cell disease with approximate prevalence at birth in different communities and some of the major clinical and hematological differences. This assessment includes three potential genetic factors influencing hematology and clinical outcome in HbSS, the beta globin haplotype, alpha thalassemia, and persistence of fetal hemoglobin (HbF). EXPERT OPINION: The author is a clinician with experience of sickle cell disease primarily in Jamaica but also in Greece, Uganda, Saudi Arabia, and India. It is therefore necessarily an account of clinical data and does not address current debates on molecular mechanisms. Most data derive from Jamaica where efforts have been made to reduce any symptomatic bias by long-term follow-up of patients all over the Island and further reduced by a cohort study based on newborn screening, which has been in operation for over 48 years.


Assuntos
Anemia Falciforme , Talassemia alfa , Anemia Falciforme/diagnóstico , Anemia Falciforme/epidemiologia , Anemia Falciforme/genética , Variação Biológica da População , Estudos de Coortes , Hemoglobina Fetal/genética , Haplótipos , Hemoglobina Falciforme/genética , Humanos , Recém-Nascido , Talassemia alfa/epidemiologia , Talassemia alfa/genética , Globinas beta/genética
20.
Cureus ; 13(2): e13367, 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33754095

RESUMO

Introduction Beta-thalassemia is among the most common monogenic disorders in the Arabian Peninsula. This study aimed to investigate the ß-globin (HBB) haplotypes among ß-thalassemia patients in Saudi cohort which have potential implications in understanding the clinical care of patients and population genetic factors associated with ß-thalassemia. Methods We analyzed 60 ß-thalassemia patients. Male/female distribution for ß-thalassemia was 58.33%/41.66%. Results of hematological parameters and indices were obtained from the database. HBB haplotyping assay was performed for four specific loci of the HBB gene cluster using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Results HBB haplotyping assay identified three novel patterns namely haplotype 1, haplotype 2, and haplotype 3 and three common African haplotypes including Benin, Senegal, and Cameron. The frequency of haplotype 1 was the highest among the studied samples (62%, n = 37) with 56.76% (n = 21) observed in males compared to 43.24% (n = 16) in females. This was followed by Senegal, haplotype 2, Benin and haplotype 3 with similar percentage, and Cameron haplotype with 18%, 12%, 3% and 2%, respectively. The relationship between these haplotypes and various hematological parameters was calculated and our study found no significant relationship (p-value >0.05). Conclusion Our study indicated the importance of finding out types of ß-globin haplotypes as novel types being discovered. Though no statistically significant association was identified among all the haplotypes in terms of hematological parameters, Cameroon or Benin haplotypes had the mildest form because they have the highest means among all parameters. Further studies need to be carried out on a larger population to detect the frequency of each specific mutation in each haplotype among ß-thalassemia patients. This would help to re-address the question of the origin(s) of the ß-thalassemia.

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