Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many mutant hemoglobins and hemoglobinopathies can be identified with a high degree of specificity in the routine clinical laboratory. The most frequent abnormalities--those involving Hb S or C--are usually easily detectable in small amounts of sample analyzed by two simple methods of electrophoresis: cellulose acetate at pH 8.5 and citrate agar at pH 6. Some rarer mutants, e.g., Hb O, Hope, and Camden, can also be recognized by these two methods. Presumptive identification of other relatively frequent mutants, such as Hb D Los Angeles (Punjab) and Hb G Philadelphia, can be accomplished with additional data obtained from globin electrophoresis on cellulose acetate in acidic and alkaline buffers containing urea and 2-mercaptoethanol (or dithioerythritol). Electrophoretic profiles are presented of about a dozen hemoglobins likely to be encountered in screening programs in the U.S. Methods are also presented for identifying other genetic hemoglobin abnormalities--various types of thalassemia, Hb M, unstable hemoglobins, and those of the newborn.
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PMID:Methods for detection of hemoglobin variants and hemoglobinopathies in the routine clinical laboratory. 40 71

Three patients with a relatively mild form of beta O-thalassemia who did not require regular blood transfusions are described. Globin synthesis was studied by gel filtration and urea-carboxymethylcellulose chromatography of stroma-free hemolysates prepared from peripheral blood and bone marrow cells labeled in vitro with 14C-leucine. gamma/alpha Synthetic ratios in peripheral blood were in the same range as in patients with the severe clinical form of beta O-thalassemia, while gamma/alpha synthetic ratios in bone marrow cells were higher than in that group of patients. The size of the free alpha-chain pool measured in one case was smaller than in other patients with "classical" Cooley anemia. It is concluded that the severity of the clinical course in beta O-thalassemia does not correlate with the imbalance in alpha verus gamma chain synthesis in peripheral blood and is determined by the synthetic ratio in bone marrow cells, where the bulk of hemoglobin synthesis takes place.
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PMID:Beta O-thalassemia intermedia. 66 61

In order to determine if mutant hemoglobins can be identified by relatively simple methods, a Working Group of the ICSH Expert Panel on Abnormal Hemoglobins and Thalassemia analyzed 17 hemolysates containing 14 different mutant hemoglobins by four electrophoretic methods: (1) cellulose acetate in alkaline buffers, (2) citrate agar pH 6.0, (3) urea 2-mercaptoethanol buffer pH 8.9, and (4) urea 2-mercaptoethanol buffer pH 6.0. The examined mutants included several of great numerical and clinical importance as well as some rare ones, namely, HbS, C, D Los Angeles (Punjab), E, G Philadelphia, N Baltimore, and O Arab; also Hb Ft. Worth, Montgomery, Winnepeg, Rush, Q India, Bethesda, and Lepore. Comparative mobilities of these hemoglobins in all of the methods are presented here. The combined data permit their presumptive identification, often with a high degree of specificity. The system has been applied in Iran, where the four prevalent mutants can be differentiated by these methods, at considerable saving of time and resources previously expended on structural analyses. It is proposed as a basis for an ICSH Tentative Standard. There is little doubt that this presumptive identification of hemoglobin variants by simple electrophoresis will be improved or complemented by the introduction of newer techniques, such as immunologic analysis. However, for the present and for some time to come, the system outlined here should be found valuable. The present report does not concern itself with the numerous auxiliary techniques involved in the identification of abnormal hemoglobins-sickle-cell test, solubility tests, lability test--and no claim is made that the simple system described here eliminates these other techniques from the diagnostic armamentarium of the laboratory.
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PMID:Simple electrophoretic system for presumptive identification of abnormal hemoglobins. By the International Committee for Standardization in Hematology. 69 90

Reticulocytes, isolated from the blood of sickle cell trait donors with either low (25-30%) or high (40-42%) haemoglobin S(Hb S) concentrations, were incubated with [3H]leucine for various times from 1.25 to 60 min. Samples of the total soluble fractions of the cells were denatured with urea and mercaptoethanol. The mixtures were analysed by electrophoresis on cellulose acetate strips. The specific radioactivities (dpm/mg) of the separated betaS and betaA globin chains were determined. The betaS/betaA ratios of globin chain specific radio activities in the reticulocytes of the 'low Hb S' donors decreased gradually from initial values higher than 1.30 to values near unity. These data suggested that faster turnover of some of the soluble, newly synthesized betaS chains compared to the newly synthesized betaA chains could explain part, but not all, of the disparity in concentrations of Hbs S and A in these people. When reticulocytes from 'high Hb S' donors were 3H-labelled for times longer than 5 min, the betaS/betaA specific radioactivity ratios remained at or near unity. This result suggested that newly synthesized betaS chains were not turning over selectively in these cells. Instead, there was a relative decrease in betaS chain synthesis proportional to the difference in blood concentrations of Hb S and Hb A. Additional calculations suggested that the more rapid turnover of newly synthesized betaS chains in the 'low Hb S' reticulocytes could explain the difference in Hb S concentrations between 'high and low Hb S' people. These results are consistent with previous reports that an alpha-thalassaemia gene, present in 'low Hb S' but absent in 'high Hb S' donors, may be responsible for the selective turnover of betaS chains.
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PMID:betaS Chain turnover in reticulocytes of sickle trait individuals with high or low concentrations of haemoglobin S. 125 71

To study the potential of multivariate classification methods in order to obtain more insight into abnormal laboratory data from patients with sickle cell disease, we investigated standard haematological and clinical chemical variables of 18 controls and 37 apparently healthy persons with heterozygous sickle cell disease (Hb AS), all women, using both univariate and multivariate classification methods. In the univariate method, those with Hb AS showed decreased serum log aspartate aminotransferase (log AST) activity, mean corpuscular volume and mean corpuscular haemoglobin (MCH) and increased sodium concentration. The multivariate method identified sodium, potassium, urea, uric acid, log AST, alanine aminotransferase and MCH as the variables that produced maximal separation between persons with Hb As and controls. It increased the 'non-error rate' for classification of persons with Hb AS by 16.4% compared with classification based on the variable, MCH, that produced maximal separation by the univariate method. The frequency distribution of percentage Hb S in the Hb AS group proved bimodal with maximal separation at 37.0% Hb S. The subgroup with 37.0% or less (n = 16) was considered to have concomitant heterozygous alpha-thalassaemia-2. In the univariate method the subgroup characterized by greater than 37.0% Hb S (n = 21) had increased serum sodium and uric acid concentrations, perhaps related to sickle cell nephropathy, whereas the subgroup with less than or equal to 37% Hb S did not. The multivariate method added information to the univariate method by additionally identifying abnormalities in serum potassium and urea concentrations in the former subgroup.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Potential of descriptive linear discriminant analysis for studying clinical chemical and haematological data from persons with heterozygous sickle cell disease. 189 49

Thirty-six pregnancies in 25 families at risk of beta-thalassaemia major received prenatal diagnosis. Chorionic villus sampling or amniocentesis was done in 35 pregnancies to obtain fetal cells for DNA linkage study, for which Southern blotting and DNA hybridization were used to detect seven restriction fragment length polymorphisms (RFLPs) within the beta-globin gene cluster: epsilon-HincII, G gamma-HindIII, A gamma-HindIII, phi beta-HincII, 3' phi beta-HincII, beta-AvaII, and 3' beta-BamHI. beta-Thalassaemia major was diagnosed in seven and excluded in 22 pregnancies. In the remaining six cases, beta-thalassaemia major could not be excluded. In these six pregnancies and another one with late booking, ultrasound-guided cordocentesis was performed at the 22nd to 27th week of gestation. Globin chain composition was determined with urea-acetic acid-Triton X-100-12 per cent polyacrylamide gel electrophoresis. beta-Thalassaemia major was diagnosed in two fetuses and excluded in the other five. Eleven fetuses (in which beta-thalassaemia major was excluded) have been delivered and are healthy at more than 5 months old. DNA linkage analysis coupled with globin chain electrophoresis provides an effective way for prenatal diagnosis of beta-thalassaemia major, although these methods are being replaced by more direct detection techniques using oligonucleotide probes.
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PMID:DNA polymorphism and globin chain analysis in the prenatal diagnosis of beta-thalassaemia major in Taiwan. 197 94

The influence of the alpha-thalassaemia gene on the haematological, biochemical and clinical presentation of sickle cell anaemia (SCA) was investigated in Saudi patients with 1 or 2 alpha-gene deletions. The results were compared to the results obtained in SCA patients without alpha-thalassaemia. In SCA patients with 2 gene deletions (homozygous alpha-thalassaemia 2), the mean cell volume, mean cell haemoglobin and Hb F were significantly lower (p less than 0.05), while packed cell volume and Hb A2 level were considerably higher (p less than 0.05) than in the SCA patients without alpha-thalassaemia. RBC and haemoglobin were higher in the former group, but the difference was not statistically significant. Patients with 1 gene deletion had intermediate values. Among the biochemical parameters, the bilirubin level was highest in patients with 1 gene deletion. Triglyceride, cholesterol, creatinine and urea levels were lower in all SCA patients, while alkaline phosphatase (ALP) and transaminases were elevated. The increase in the levels of ALP, SGOT and SGPT was maximum in the SCA patients with 2 gene deletions, but except for SGOT, the increase was not statistically significant. The retrospective analysis of the clinical data revealed that SCA patients with alpha-thalassaemia had fewer complications and had received fewer blood transfusions than the patients without alpha-thalassaemia.
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PMID:Clinical manifestation and laboratory findings of sickle cell anaemia in association with alpha-thalassaemia in Saudi Arabia. 242 Jan 34

Members of a Cambodian family with an undiagnosed hypochromic, microcytic anaemia were found by haemoglobin and DNA analysis to have five interacting globin gene abnormalities. One child has Hb E and typical Hb H disease, while his mother has the form of Hb H disease associated with Hb Constant Spring interacting with Hb E. Quantitation of Hbs E and A2 by globin chain separation and triton/urea gel electrophoresis support the concept that Hb H/Constant Spring disease is a more severe form of alpha thalassaemia than Hb H disease. This family illustrates how the remarkably high prevalence of globin gene abnormalities in Southeast Asians can give rise to a series of atypical thalassaemic phenotypes, and how they can be defined by direct globin gene analysis.
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PMID:Interaction of five globin gene abnormalities in a Cambodian family. 375 62

A mild anemia (hemoglobin 9 g/dl) was found in a patient from Seville (Spain) with marked morphological abnormalities in the peripheral blood smear. The red cell osmotic fragility showed a mild resistance curve with a mean cell fragility (MCF) of 0.375% NaCl (normal = 0.450). Chemical Chemical and thermal instability test and search for inclusion bodies gave positive results. Hemoglobin electrophoresis at pH 8.9 revealed absence of Hb A, a major component of fast mobility (94%), and increased Hb F and Hb A2 levels (1.5% and 4.6%, respectively). The fast fraction, isolated and purified by means of cellulose acetate electrophoresis, precipitated in acid acetone and treated with urea 8 M and mercaptoethanol, revealed an anomalous beta chain. Trypsin-digested globin peptides were separated by high-voltage electrophoresis at pH 6.4 and ascendant chromatography. With differential staining, an extra peptide was detected in an unusual site, more anodic than alpha Tp4 but in lower position. Peptide map of the fast beta chain, stained with ninhydrin, and also for Tyr, confirmed the position of the new peptide and the absence of the usual beta Tp13. The new peptide, separated by high-voltage electrophoresis at pH 3.5, revealed absence of Val and the presence of an additional Glu residue, which should appear only in position beta 126. The diagnosis of Hb Hofu (alpha 2 beta 2 126 Val----Glu; H4) was reached, thus interpreting its increase and the absence of Hb A, as an association with beta o-thalassemia, producing a mild hemolytic anemia. Evidence was obtained that Hb Hofu is a mild unstable hemoglobin variant.
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PMID:Hemoglobin Hofu associated with beta 0-thalassemia. 392 70

Hb Knossos is a beta-chain variant (beta 27 Ser----Ala) that is unrecognizable by conventional separation methods but detectable by globin electrophoresis on urea-Triton X-acrylamide gels or by IEF. Hb Knossos is characterized by reduced synthesis and by interaction with beta-thalassemia, in which the double heterozygotes display typical features of thalassemia intermedia. The present paper summarizes the salient genetic, clinical, and biochemical characteristics of five such cases hitherto identified in three families along with the same features on 12 heterozygous Hb Knossos carriers. Hb Knossos displays a slightly decreased oxygen affinity; this factor may compensate in part for the severe anemia of the double heterozygotes. Hb Knossos is relatively rare in our population, since a prospective survey on 610 individuals has failed to disclose any heterozygotes. However, the mutation appears to have spread over the Mediterranean countries and may be more common elsewhere.
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PMID:Hemoglobin Knossos: a clinical, laboratory, and epidemiological study. 394 30


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