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PubMed1991

[Rapid prenatal diagnosis for thalassemia].

By means of polymerase chain reaction (PCR), prenatal diagnoses were successfully made in 20 fetuses at risk for beta-thalassemia homozygotes and 2 at risk for Bart's hydrops fetalis. Six pregnancies with homozygotes or double heterozygotes of beta-thalassemia were therapeutically terminated. Ten fetuses were predicted to be beta-thalassemia heterozygotes and 4 were normal. Hydrops fetalis was excluded in two fetuses. The predictions have so far been confirmed after delivery or therapeutic abortion, and no discrepancy was found. The advantages of this technique are discussed.

Female↗
PubMed1991

Presacral extramedullary hematopoiesis in thalassemia intermedia.

Extramedullary hematopoiesis is manifested by several clinical hematologic disorders including beta-thalassemia major and thalassemia intermedia. We report an unusual case of extramedullary hematopoiesis, which presented as a painful presacral mass in a patient with beta-thalassemia intermedia. The diagnosis was confirmed by a needle biopsy guided by computed tomography. The patient responded well to radiation therapy to the sacral region.

Adult↗
PubMed1991

Prenatal diagnosis of beta-thalassemia.

In this review I have discussed the state of our knowledge of the molecular basis of beta-thalassemia and its prenatal diagnosis. Improved but more complicated genetic counselling is now available as a result of our increased knowledge of the effects of various defects in the beta-globin gene. Our knowledge of the heterogenous molecular basis of the thalassemia syndromes has become very impressive and it is hoped that effective therapy will soon follow. However, for the present, prevention of the birth of affected children is the most effective means of reducing the suffering associated with the thalassemia syndromes, and prevention of this type is succeeding in many parts of the world, including North America.

Ethnicity↗
PubMed1991

[Osteoarthropathy in beta-thalassemia].

A total of 45 patients with beta-thalassemia and 30 patients with thalassemia intermedia underwent clinical and x-ray examinations. Electron microscopy was used to examine biopsy specimens of the synovial membrane from 6 patients with homozygous thalassemia intermedia. It has been revealed that damage to the osseous system and joints is of systemic nature and depends on the clinical form of the pathological process. Morphological methods have demonstrated abnormal metabolism of iron with its deposition in the tissues and impairment of the vessels of the microcirculatory bed.

Adolescent↗
PubMed1991

[Molecular analysis of thalassemia].

Molecular analysis of gene structure using PCR related techniques has been described. These techniques were applied to analysis of the beta-globin gene from Japanese individuals with beta-thalassemia. We found one promoter mutation, two splicing mutations, two frameshift mutations, one nonsense mutation. We also detected three different mutations within the third exon. They produced highly unstable globin variants, leading a dominantly inherited beta-thalassemia phenotype. Six of nine different mutations seem to originate in Japanese. Characteristics of molecular defects of Japanese beta-thalassemia was discussed in terms of malaria hypothesis.

Base Sequence↗
PubMed1991

Diagnosis of thalassemia using cDNA amplification of circulating erythroid cell mRNA with the polymerase chain reaction.

We have developed a technique to diagnose the alpha- and beta-thalassemia (thal) syndromes using the polymerase chain reaction to amplify cDNA copies of circulating erythroid cell messenger RNA (mRNA) so as to quantitate the relative amounts of alpha-, beta-, and gamma-globin mRNA contained therein. Quantitation, performed by scintillation counting of 32P-dCTP incorporated into specific globin cDNA bands, showed ratios of alpha/beta-globin mRNA greater than 10-fold and greater than fivefold increased in patients with beta 0- and beta (+)-thal, respectively, as well as a relative increase in gamma-globin mRNA levels. Conversely, patients with alpha-thalassemia showed a decreased ratio of alpha/beta-globin mRNA proportional to the number of alpha-globin genes deleted. This methodology of ascertaining ratios of globin mRNA species provides a new, simplified approach toward the diagnosis of thalassemia syndromes, and may be of value in other studies of globin gene expression at the transcription level.

Base Sequence↗
PubMed1991

Coexistence of hereditary spherocytosis and beta-thalassemia: case report of severe hemolytic anemia in an American black.

The first reported case of hereditary spherocytosis (HS) and beta-thalassemia in an American black is presented. The diagnosis rested on clinical presentation, family history and specialized laboratory findings. The tendency toward hemolysis of spherocytes and thalassemia red cells may explain the severity of anemia in this patient. The clinical course of these coexistent diseases and the role of splenectomy in relieving the hemolytic component caused by hereditary spherocytosis are described. A detailed review of the literature on HS and beta-thalassemia is also included.

Adult↗
PubMed1991

In vivo platelet activation in beta-thalassemia major reflected by increased platelet-thromboxane urinary metabolites.

Increased frequency of thromboembolic events has been recently observed in patients with beta-thalassemia major (TM). Platelet function anomalies including impaired aggregation, increased circulating aggregates, and our finding of shortened platelet survival indicate that platelets may be involved in the hypercoagulability in thalassemia. Consequently, we used a technique based on thin layer chromatography purification and enzyme immunoassay to measure urinary metabolites of thromboxane A2 (TXA2) and prostacyclin (PGI2) in nine splenectomized patients with beta-TM regularly transfused, five non-splenectomized patients with beta-thalassemia intermedia (TI), and 20 healthy individuals. A significant 4- to 10-fold increase was observed in the urinary excretion of 2,3-dinor-TXB2, 11-dehydro-TXB2 and 2,3-dinor-6-keto-PGF1 alpha in patients with TM and TI as compared with healthy controls. No significant differences were found in the concentrations of these metabolites between TM and TI patients. Six TM patients received a very low dose of aspirin (20 mg/day) for 7 days. A significant decrease was observed in the urinary concentrations of 2,3-dinor-TXB2 and 11-dehydro-TXB2 derived from platelets. However, the levels of urinary 2,3-dinor-6-keto-PGF1 alpha reflecting vascular production and TXB2 and 6-keto-PGF1 alpha originating from the kidney were not significantly changed. These results are consistent with those of increased in vivo production of TXA2 because of endogenous platelet activation.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Red cell distribution width, free erythrocyte protoporphyrin, and England-Fraser index in the differential diagnosis of microcytosis due to iron deficiency or beta-thalassemia trait. A study of 200 cases of microcytic anemia.

Microcytic anemias are often encountered in clinical practice. In most cases they are due to iron deficiency, but in some geographical areas other diagnoses, such as that of beta-thalassemia trait, must be considered. In some cases, the hematological data presented by the automated hemogram may be very similar in both entities, showing moderate anemia, microcytosis, and increased red blood cells. From a practical point of view, it may be important to make an "at-first sight" diagnosis using simple parameters that may readily be obtained from the hemogram or from the laboratory. We have assessed the usefulness of RDW (red cell distribution width), of the England-Fraser index and of free erythrocyte protoporphyrin determination in predicting iron deficiency anemia or beta-thalassemia trait. Our results suggest that the most accurate of these parameters is the England-Fraser index, but that a presumptive diagnosis of beta-thalassemia trait can correctly be made if RDW and FEP values are near normality.

Adolescent↗
PubMed1990

[Studies of beta-thalassemia mutations and prenatal diagnosis in Guangxi, Guangdong and Sichuan Provinces of south China].

beta-Thalassemia is one of the most common single gene disorders in South China, and ten different point mutations and frameshifts have been observed among Chinese. We studied 150 chromosomes of 95 beta-thalassemia patients from Guangxi, Guangdong and Sichuan Provinces using the polymerase chain reaction followed by dot hybridization with specific oligonucleotide probes. The most common mutations were the frameshift at codon 41-42 and the nonsense mutation at codon 17 in Guangxi and Sichuan, and the codon 41-42 frameshift and IVS-II-654 mutation in Guangdong. The A-G mutation at -28 of the promoter was common in Sichuan but not in the other two provinces. Three mutations, -30, IVS-I-1 and IVS-I-5, were not observed. A prenatal diagnosis program using these techniques has been initiated based on these data. Fourteen pregnancies at risk for beta-thalassemia have been diagnosed successfully.

China↗
PubMedDate not supplied

[The echocardiographic characteristics of cardiac lesions in beta-thalassemia].

The authors submit the results of clinicoechocardiographic investigations of 35 patients with beta-thalassemia aged from 4 to 37 years of whom 23 patients were with acute beta-thalassemia, 6 with an intermediary form and 6 with a heterozygotic form of the disease. Various echocardiographic changes were observed in patients with acute and intermediary forms of beta-thalassemia, i.e. prolapse of the mitral valve (52 and 50 per cent), the presence of fluid in the pericardium (13 and 17 per cent), structural changes in the valvular apparatus (56 and 83 per cent), disorders of the inotropic and diastolic functions of the heart.

Adolescent↗
PubMed1990

[Successful pregnancy outcome in a patient with HbE/beta (0)-thalassemia].

Successful pregnancy outcome is described in a patient with hemoglobin E/beta(0)-thalassemia which is expressed as thalassemia major. A 21 year-old Laotian female complicated by severe anemia became pregnant. The diagnosis of hemoglobin E/beta (0)-thalassemia was made by hemoglobin analysis. The fetal weight estimated by abdominal echogram decreased during pregnancy. She received blood transfusions, in order to improve intrauterine growth retardation. Hemoglobin concentration was maintained at the level greater than 9 g/dl. Fetal growth was improved by the treatment. A normal full-term male infant was born by a caesarean section, and splenectomy was performed at the same time.

Adult↗
PubMed1990

[Possibility of the development of non-transfusion hemosiderosis in beta-thalassemia, caused by association with HLA-linked hemochromatosis].

The data of HLA-haplotyping were used as an allele marker controlling hereditary hemochromatosis in 23 patients with beta-thalassemia. The results obtained have permitted a conclusion that hemosiderosis in patients with beta-thalassemia may be caused by association of beta-thalassemia gene with hereditary hemochromatosis. Early diagnosis of hyperferremia is of great prognostic importance as the adequate treatment timely conducted can prevent the development of irreversible changes in the patients.

Adolescent↗
PubMed1990

Oxidative denaturation of red blood cells in thalassemia.

We believe that on the basis of all available data, severe oxidative damage occurs in alpha- and beta-thalassemic RBCs, as depicted schematically in Fig 6. The differences in the severity and pattern of the oxidative damage may be related to the type and, perhaps, quantity of precipitated globin chains. The detrimental effect of the excess chains is multifold. In the process of globin-chain precipitation, free radicals are generated. The end product of the precipitated hemoglobin chains is heme, from which eventually iron and globin are liberated. Globin chains have been found to interact and disrupt the RBC membrane, damaging the cytoskeleton. The role of heme has not yet been studied in detail in thalassemic RBCs. However, there is some evidence that it participates in damaging RBCs in other types of hemoglobinopathies. Excess of iron is known to be a catalyst of peroxidation via the Fenton reaction, causing damage to the various RBC membrane components (lipids, proteins, etc). The denatured hemaglobin, in the form of hemichromes, aggregates with protein 3, forming Actual proof of excessive free radical production in thalassemia is still warranted. It will not be easy to document since the amount of superoxide dismutase in RBCs is above and beyond that required for neutralizing excess amount of superoxide. The more active radicals, particularly hydroxyl free radical, are difficult to measure because they are so active an interact immediately with any given substrate in their vicinity. In addition, we have to better understand the finding of excess membrane lipids in thalassemic RBCs and whether there are changes in the formation and propagation of lipid peroxidation in these cells compared with normal RBCs. Regarding the proteins, further understanding is required concerning the exact type and sites of oxidation that occurs in the beta-thalassemia 4.1 protein, and whether the damage found in alpha-thalassemia is due to oxidation of ankyrin itself or its entrapment within the complex of the precipitated hemichromes of beta chains. What is the role of the different globin chain oxidation and precipitation in generating such different cytoskeletal protein alterations? Another point that needs to be elucidated is the role of different kinds of antibodies that are attached to the newly exposed antigenic sites on the thalassemic RBC membranes.(ABSTRACT TRUNCATED AT 400 WORDS)

Erythrocytes↗
PubMed1985

[Differential erythrocyte parameters in thalassemia minor and hyposideremic syndromes].

In order to estimate the validity of the discriminant function suggested by England e Fraser, we have determined the number of red cells (RBC) mean cell volume (MCV), hemoglobin mean concentration (MCV) and red cells distribution (RDW) in normal subjects, iron-deficient patients and uncomplicated thalassemia minor. The results obtained allow us to point out that RDW in the patients with thalassemia are higher than in normal subjects. In patients with iron-deficiency, instead, RDW medium is increased, but with a remarkable distribution of values. These results point out that anisocytosis is higher in iron-deficiency than in thalassemia.

Anemia, Hypochromic↗
PubMed1989

Homozygous beta-thalassemia without anemia.

A 37-year-old man of Guyanese origin was found to have homozygous beta-thalassemia without anemia. There were no physical stigmata of thalassemia. The hematocrit value was 41 to 45.8, the mean corpuscular volume was 61 fL, and the mean corpuscular hemoglobin was 18.9 pg. The HbF was 45% with a G gamma:A gamma ratio of 3:1. An acid elution preparation of the peripheral blood showed heterogeneous distribution of HbF, but all erythrocytes stained for fetal hemoglobin. The beta/alpha synthesis ratio in the peripheral blood was 0.25; the (beta + gamma)/alpha ratio was 0.55. Haplotype analysis revealed homozygosity for the -+-+ + + + pattern (Senegal, type IX) at seven polymorphic restriction sites within the beta-like gene complex. Digestion of DNA with Xmnl indicated that the -158 C-to-T transition was present in both beta-globin gene clusters. Oligomer hybridization analysis demonstrated homozygosity for the -29 A-to-G mutation in the beta-globin promoter region. Although this form of thalassemia can cause transfusion-requiring anemia, the high-HbF, high-G gamma phenotype associated with the linked +-+ + subhaplotype and -158 C-to-T substitution appears to have ameliorated the disease in this subject.

Adult↗
PubMedDate not supplied

Double heterozygosity for hemoglobin Malmö [beta 97 (FG 4) His----Gln] and beta-thalassemia traits.

A 32-year-old Sicilian man had marked erythrocytosis (Hb = 23.0 g/dl, RBC = 10.5 x 10(12)/l, MCV = 71 fl, Hct = 84-92%, a 4.5 times increase in total erythropoies) and saphenous system varices, without other clinical abnormalities. By Hb electrophoresis, an abnormal Hb migrating slightly more anodally than Hb A was found. HbA0 was almost completely absent. The abnormal Hb was recognized to be Hb Malmö [beta 97 (FG4) His-Gln], a human Hb variant with greatly increased oxygen affinity. The patient was also a carrier of the beta-thalassemia trait. The father of the propositus was a heterozygous carrier of Hb Malmö (about 40% of total Hb), while his mother had only a beta-thalassemia condition. This is the first reported case of double heterozygosity for both Hb Malmö and beta-thalassemia, thus producing complete absence of normal Hb.

Adult↗
PubMed1989

A novel ochre mutation in the beta-thalassemia gene of a Thai. Identification by direct cloning of the entire beta-globin gene amplified using polymerase chain reactions.

The beta-globin genes from a Thai patient compound heterozygous for beta-thalassemia and HbE disease were investigated. The 3.0-kilobase fragment containing the entire beta-globin gene was amplified by polymerase chain reaction, using Taq DNA polymerase followed by direct cloning of the amplified product into plasmid DNA. Sequence analysis of the thalassemia gene revealed only one base change, a C-A transversion within codon for an amino acid 35. This new mutation creates a premature terminator, TAA, an ochre codon, and results in a beta 0-thalassemia phenotype. The same result was obtained when this mutation was analyzed using a conventional cloning technique, direct sequencing of the amplified product, and hybridization with allele-specific oligonucleotide probes. No misincorporation was detected in the sequence analysis of the 3.0-kilobase insert of five clones of the amplified products obtained from genomic DNA of a normal individual. This approach is a rapid and accurate method for molecular cloning of the beta-globin gene and also other genes, the partial nucleotide sequences of which are known.

Base Sequence↗