scholarly journals Molecular characterization of beta-thalassemia intermedia in patients of Italian descent and identification of three novel beta-thalassemia mutations

Blood ◽  
1991 ◽  
Vol 77 (6) ◽  
pp. 1342-1347 ◽  
Author(s):  
S Murru ◽  
G Loudianos ◽  
M Deiana ◽  
C Camaschella ◽  
GV Sciarratta ◽  
...  
Keyword(s):  
Blot Analysis ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Italian Population ◽  
Beta Globin ◽  
Thalassemia Intermedia ◽  
Dot Blot ◽  
Beta Globin Gene ◽  
Dot Blot Analysis ◽  
Thalassemia Mutation

In this study, we have defined by dot-blot analysis with allelic specific oligonucleotide probes or direct sequencing on amplified DNA the beta-thalassemia mutations in a large group of patients (23) of Italian descent with thalassemia intermedia. These patients had one parent with either the silent beta-thalassemia carrier phenotype or borderline-normal hemoglobin A2 (HbA2) levels (2.5% to 3.5%). Nearly all were genetic compounds for a severe beta-thalassemia mutation and a beta-thalassemia mutation associated with high residual output of beta- globin chains (beta + intervening sequence [IVS]-I-nt6, beta -87, beta - 101), indicating that inheritance of a mild beta-thalassemia allele, even in a single dose, is the most common molecular mechanism producing thalassemia intermedia in the Italian population. In three cases, in whom we failed to define by dot-blot analysis the mutations, we sequenced the beta + globin gene and found three novel beta-thalassemia mutations, which are certainly very rare because they have been hitherto detected solely in a single patient. These mutations consist of: (1) a T-A substitution at position 2 of IVS-I, in a patient compound heterozygote for this mutation and the -87 promoter mutation; (2) a G-C substitution at position 844 of IVS-II, in a patient heterozygous for this mutation who showed normal sequences at the in trans beta-globin gene (The reason for the presence of clinical manifestations in a beta-thalassemia heterozygote has not been defined.); and (3) a deletion of one nucleotide (-T) at codon 126, resulting in a frameshift and readthrough of the 5′ untranslated region and most likely producing an elongated Hb molecule of 156 amino acid residues, in a patient heterozygous for this mutation with normal beta- globin gene sequences at the other locus.

scholarly journals Molecular characterization of beta-thalassemia intermedia in patients of Italian descent and identification of three novel beta-thalassemia mutations

Blood ◽  
1991 ◽  
Vol 77 (6) ◽  
pp. 1342-1347 ◽  
Author(s):  
S Murru ◽  
G Loudianos ◽  
M Deiana ◽  
C Camaschella ◽  
GV Sciarratta ◽  
...  
Keyword(s):  
Blot Analysis ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Italian Population ◽  
Beta Globin ◽  
Thalassemia Intermedia ◽  
Dot Blot ◽  
Beta Globin Gene ◽  
Dot Blot Analysis ◽  
Thalassemia Mutation

Abstract In this study, we have defined by dot-blot analysis with allelic specific oligonucleotide probes or direct sequencing on amplified DNA the beta-thalassemia mutations in a large group of patients (23) of Italian descent with thalassemia intermedia. These patients had one parent with either the silent beta-thalassemia carrier phenotype or borderline-normal hemoglobin A2 (HbA2) levels (2.5% to 3.5%). Nearly all were genetic compounds for a severe beta-thalassemia mutation and a beta-thalassemia mutation associated with high residual output of beta- globin chains (beta + intervening sequence [IVS]-I-nt6, beta -87, beta - 101), indicating that inheritance of a mild beta-thalassemia allele, even in a single dose, is the most common molecular mechanism producing thalassemia intermedia in the Italian population. In three cases, in whom we failed to define by dot-blot analysis the mutations, we sequenced the beta + globin gene and found three novel beta-thalassemia mutations, which are certainly very rare because they have been hitherto detected solely in a single patient. These mutations consist of: (1) a T-A substitution at position 2 of IVS-I, in a patient compound heterozygote for this mutation and the -87 promoter mutation; (2) a G-C substitution at position 844 of IVS-II, in a patient heterozygous for this mutation who showed normal sequences at the in trans beta-globin gene (The reason for the presence of clinical manifestations in a beta-thalassemia heterozygote has not been defined.); and (3) a deletion of one nucleotide (-T) at codon 126, resulting in a frameshift and readthrough of the 5′ untranslated region and most likely producing an elongated Hb molecule of 156 amino acid residues, in a patient heterozygous for this mutation with normal beta- globin gene sequences at the other locus.

A C----T substitution at nt--101 in a conserved DNA sequence of the promotor region of the beta-globin gene is associated with “silent” beta-thalassemia

Blood ◽  
1989 ◽  
Vol 73 (6) ◽  
pp. 1705-1711 ◽  
Author(s):  
JM Gonzalez-Redondo ◽  
TA Stoming ◽  
A Kutlar ◽  
F Kutlar ◽  
KD Lanclos ◽  
...  
Keyword(s):  
Globin Gene ◽  
Beta Thalassemia ◽  
Nucleotide Position ◽  
Beta Globin ◽  
Dot Blot ◽  
Sequence Analyses ◽  
Beta Globin Gene ◽  
Chain Synthesis ◽  
Thalassemia Mutation

Sequence analyses and dot-blot analyses with synthetic oligonucleotide probes have identified eight individuals in three Turkish families and one Bulgarian family with one chromosome having a C----T mutation at nucleotide position--101 relative to the Cap site of the beta-globin gene. This nucleotide is part of one of the conserved blocks of nucleotides within the promoter region; in vitro expression analyses with the chloramphenicol acetyltransferase system showed that this substitution will decrease the effectiveness of transcription. Five subjects had a thalassemia intermedia due to the additional presence of a known classical high hemoglobin (Hb) A2 beta-thalassemia mutation on the second chromosome; their hematologic condition was relatively mild. The three persons with a heterozygosity for the--101 C----T mutation had normal hematologic data without microcytosis but with high-normal levels of Hb A2 and a mild imbalance in chain synthesis. The newly discovered mutation is considered one of the silent types of beta- thalassemia. It is relatively rare because it was absent among several hundred normal and beta-thalassemia chromosomes.

scholarly journals A C----T substitution at nt--101 in a conserved DNA sequence of the promotor region of the beta-globin gene is associated with “silent” beta-thalassemia

Blood ◽  
1989 ◽  
Vol 73 (6) ◽  
pp. 1705-1711 ◽  
Author(s):  
JM Gonzalez-Redondo ◽  
TA Stoming ◽  
A Kutlar ◽  
F Kutlar ◽  
KD Lanclos ◽  
...  
Keyword(s):  
Globin Gene ◽  
Beta Thalassemia ◽  
Nucleotide Position ◽  
Beta Globin ◽  
Dot Blot ◽  
Sequence Analyses ◽  
Beta Globin Gene ◽  
Chain Synthesis ◽  
Thalassemia Mutation

Abstract Sequence analyses and dot-blot analyses with synthetic oligonucleotide probes have identified eight individuals in three Turkish families and one Bulgarian family with one chromosome having a C----T mutation at nucleotide position--101 relative to the Cap site of the beta-globin gene. This nucleotide is part of one of the conserved blocks of nucleotides within the promoter region; in vitro expression analyses with the chloramphenicol acetyltransferase system showed that this substitution will decrease the effectiveness of transcription. Five subjects had a thalassemia intermedia due to the additional presence of a known classical high hemoglobin (Hb) A2 beta-thalassemia mutation on the second chromosome; their hematologic condition was relatively mild. The three persons with a heterozygosity for the--101 C----T mutation had normal hematologic data without microcytosis but with high-normal levels of Hb A2 and a mild imbalance in chain synthesis. The newly discovered mutation is considered one of the silent types of beta- thalassemia. It is relatively rare because it was absent among several hundred normal and beta-thalassemia chromosomes.

scholarly journals Molecular analysis of beta zero-thalassemia intermedia in Sardinia

Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 823-827 ◽  
Author(s):  
R Galanello ◽  
E Dessi ◽  
MA Melis ◽  
M Addis ◽  
MA Sanna ◽  
...  
Keyword(s):  
Nonsense Mutation ◽  
Frameshift Mutation ◽  
Globin Gene ◽  
Thalassemia Major ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Thalassemia Intermedia ◽  
Mild Phenotype ◽  
Beta Globin Gene ◽  
Alpha Thalassemia

Abstract In this study we have carried out alpha- and beta-globin gene analysis and defined the beta-globin gene polymorphisms in a group of patients with thalassemia intermedia of Sardinian descent. A group of patients (109) with thalassemia major of the same origin served as control. Characterization of the beta-thalassemia mutation showed either a frameshift mutation at codon 6 or a codon 39 nonsense mutation. We found that homozygotes for the frameshift mutation at codon 6 or compound heterozygotes for this mutation and for the codon 39 nonsense mutation develop thalassemia intermedia more frequently than thalassemia major. The frameshift mutation at codon 6 was associated with haplotype IX that contains the C-T change at position -158 5′ to the G gamma globin gene implicated in high gamma chain production and thus the mild phenotype. In patients' homozygotes for codon 39 nonsense mutation, those with thalassemia intermedia more frequently had the two- gene deletion form of alpha-thalassemia, or functional loss of the alpha 2 gene as compared with those with thalassemia major. In a few siblings with thalassemia major and intermedia, the thalassemia intermedia syndrome correlated with the presence of the -alpha/-alpha genotype. No cause for the mild phenotype was detected in the majority of patients who had not inherited either haplotype IX or alpha- thalassemia.

scholarly journals Molecular analysis of beta zero-thalassemia intermedia in Sardinia

Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 823-827 ◽  
Author(s):  
R Galanello ◽  
E Dessi ◽  
MA Melis ◽  
M Addis ◽  
MA Sanna ◽  
...  
Keyword(s):  
Nonsense Mutation ◽  
Frameshift Mutation ◽  
Globin Gene ◽  
Thalassemia Major ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Thalassemia Intermedia ◽  
Mild Phenotype ◽  
Beta Globin Gene ◽  
Alpha Thalassemia

In this study we have carried out alpha- and beta-globin gene analysis and defined the beta-globin gene polymorphisms in a group of patients with thalassemia intermedia of Sardinian descent. A group of patients (109) with thalassemia major of the same origin served as control. Characterization of the beta-thalassemia mutation showed either a frameshift mutation at codon 6 or a codon 39 nonsense mutation. We found that homozygotes for the frameshift mutation at codon 6 or compound heterozygotes for this mutation and for the codon 39 nonsense mutation develop thalassemia intermedia more frequently than thalassemia major. The frameshift mutation at codon 6 was associated with haplotype IX that contains the C-T change at position -158 5′ to the G gamma globin gene implicated in high gamma chain production and thus the mild phenotype. In patients' homozygotes for codon 39 nonsense mutation, those with thalassemia intermedia more frequently had the two- gene deletion form of alpha-thalassemia, or functional loss of the alpha 2 gene as compared with those with thalassemia major. In a few siblings with thalassemia major and intermedia, the thalassemia intermedia syndrome correlated with the presence of the -alpha/-alpha genotype. No cause for the mild phenotype was detected in the majority of patients who had not inherited either haplotype IX or alpha- thalassemia.

scholarly journals Mutation in thalassemia syndrome and clinical manifestation

2020 ◽  
Vol 6 (2) ◽  
pp. e29-e29
Author(s):  
Ahmad Tamaddoni ◽  
Leila Gharehdaghly ◽  
Mohammad Bahadoram
Keyword(s):  
Blood Transfusion ◽  
Molecular Basis ◽  
Globin Gene ◽  
Clinical Severity ◽  
Clinical Aspects ◽  
Beta Globin ◽  
Thalassemia Intermedia ◽  
Dot Blot ◽  
Mazandaran Province ◽  
Beta Globin Gene

Introduction: Thalassemia intermedia is a term used to define a group of patients with β thalassemia in whom the clinical severity of the disease is somewhere between the mild symptoms of the β thalassemia trait and the severe manifestations of β thalassemia major. Thalassemia intermedia shows considerable heterogeneity in phenotype and molecular basis. Objectives: The aim of this study was to identify the common mutations of beta globin gene and the relationship between genotypes and phenotypes in thalassemia intermedia patients in Mazandaran province, in the north of Iran. Patients and Methods: Fifty unrelated thalassemia intermedia patients, based on clinical and hematological characteristics including age of diagnosis, age of first blood transfusion, history of blood transfusion, mean corpuscular volume (MCV), mean cell hemoglobin (MCH), hemoglobin values, and liver and spleen status were selected. DNA of peripheral blood was extracted and common mutations in beta globin gene were analyzed by reverse dot blot (RDB) method. Results: Our study showed that 30 patients (60%) had blood transfusion. There was no obvious hepatomegaly in any of the subjects, however 40 patients (80%) showed splenomegaly among which 34 cases (68%) underwent splenectomy. Mutations analysis indicated that HBB:c.315+1G>A [IVS II-1 (G>A)] mutation was the dominant mutation and has been widely associated with the phenotypic manifestations of thalassemia intermedia patients. Conclusion: It is important to comprehend the molecular basis of thalassemia intermedia and the association between genotype and phenotype in different ethnic groups. Therefore a careful evaluation of genetic, molecular, hematological and clinical aspects is necessary to differentiate thalassemia intermedia in patients at presentation.

scholarly journals beta-thalassemia intermedia in a Brazilian patient with - 101(C > T) and codon 39 (C > T) mutations

2003 ◽  
Vol 121 (1) ◽  
pp. 28-30
Author(s):  
Sylvia Morais de Sousa ◽  
Letícia Khater ◽  
Luís Antônio Peroni ◽  
Karine Miranda ◽  
Marcelo Jun Murai ◽  
...  
Keyword(s):  
Clinical Course ◽  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Hypochromic Anemia ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Thalassemia Intermedia ◽  
Mean Cell Volume ◽  
Molecular Alterations ◽  
Brazilian Patient

CONTEXT: We verified molecular alterations in a 72-year-old Brazilian male patient with a clinical course of homozygous beta-thalassemia intermedia, who had undergone splenectomy and was surviving without regular blood transfusions. The blood cell count revealed microcytic and hypochromic anemia (hemoglobin = 6.5 g/dl, mean cell volume = 74 fl, mean cell hemoglobin = 24 pg) and hemoglobin electrophoresis showed fetal hemoglobin = 1.3%, hemoglobin A2 = 6.78% and hemoglobin A = 79.4%. OBJECTIVE: To identify mutations in a patient with the symptoms of beta-thalassemia intermedia. DESIGN: Molecular inquiry into the mutations possibly responsible for the clinical picture described. SETTING: The structural molecular biology and genetic engineering center of the Universidade Estadual de Campinas, Campinas, Brazil. PROCEDURES: DNA extraction was performed on the patient's blood samples. The polymerase chain reaction (PCR) was done using five specific primers that amplified exons and the promoter region of the beta globin gene. The samples were sequenced and then analyzed via computer programs. RESULTS: Two mutations that cause the disease were found: -101 (C > T) and codon 39 (C > T). CONCLUSIONS: This case represents the first description of 101 (C > T) mutation in a Brazilian population and it is associated with a benign clinical course.

scholarly journals The inactive beta globin gene on a gamma delta beta thalassemia chromosome has a normal structure and functions normally in vitro

Blood ◽  
1988 ◽  
Vol 71 (3) ◽  
pp. 766-770
Author(s):  
PT Curtin ◽  
YW Kan
Keyword(s):  
Globin Gene ◽  
Large Deletion ◽  
Beta Thalassemia ◽  
Ribonuclease Protection Assay ◽  
Beta Globin ◽  
Gamma Delta ◽  
Beta Globin Gene ◽  
Thalassemia Minor

We have previously described an English family with gamma delta beta- thalassemia in which a large deletion stops 25 kilobases (kb) upstream from the beta-globin gene locus, and yet the beta-globin gene is inactive in vivo. Affected family members had a beta-thalassemia minor phenotype with a normal hemoglobin A2 level. Gene mapping showed that these subjects were heterozygous for a chromosome bearing a large deletion that began in the G gamma-globin gene, extended through the epsilon-globin gene, and continued upstream for at least 75 kb. The A gamma-, delta-, and beta-globin gene loci on this chromosome were intact. To examine the possibility that an additional defect was present in the beta-globin gene, we cloned, sequenced, and examined the expression of the beta-globin gene from the affected chromosome. No mutation was found in the beta-globin gene sequence from 990 base-pairs 5′ to the cap site to 350 basepairs 3′ to the polyadenylation signal. The gene was subcloned into an expression vector and introduced into HeLa cells. Analysis of RNA derived from these cells, using a ribonuclease protection assay, revealed qualitatively and quantitatively normal transcription. Thus a structurally and functionally normal beta-globin gene is inactive in the presence of a large deletion more than 25 kb upstream. The loss of beta-globin gene function may be due to disturbance of chromatin conformation caused by the deletion or may be the result of loss of upstream sequences that are necessary for beta-globin gene expression in vivo.

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