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)

Hb Vancouver (alpha2beta2 73 (E17) ASP yieldTYR) was found in combination with betaomicron thalassemia trait in a Chinese male who presented with splenomegaly and thalassemia intermedia (3). The family study has revealed two members with beta thalassemia trait, one heterozygote for Hb E, and two heterozygotes for Hb Vancouver. The Hb Vancouver heterozygotes were clinically normal but their erythrocytes showed reduced osmotic fragility and occasional target cells.
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PMID:Clinical and hematological studies in a family with hemoglobin Vancouver. 64 Aug 52

A 6-year-old child of northern European ancestry was found to have microcytic, hypochromic anemia with an elevated level of hemoglobin A2 and an unbalanced pattern of globin chain synthesis characteristic of beta-thalassemia trait. Hematologic and globin synthesis studies of both parents yielded entirely normal results. Identification of the mother and father as the biological parents was established with a high order of reliability by determination of erythrocyte, serum, and HLA genetic markers. These findings suggest that the picture of beta-thalassemia observed in this child represents a new mutation.
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PMID:beta-Thalassemia arising as a new mutation in an American child. 67 20

The thalassemias are a heterogeneous group of genetically determined disorders of hemoglobin synthesis and can be divided into alpha-thalassemias and beta-thalassemias. The genes for these disorders are carried as relatively harmless traits which can be detected in the laboratory by a series of tests. As there are several variant genes in each group, heterozygotes for two slightly different genes occur, and interaction of these thalassemia genes with the hemoglobinopathies is quite common. Severe clinical disease usually only occurs in homozygotes, as in Cooley's anemia. The problem for the laboratory is to distinguish thalassemia trait from other causes of microcytosis and hypochromia in an economical and efficient way. The various proposed schemes are discussed, and it is suggested that detection of these traits should be part of a comprehensive screening program for hemoglobinopathies and thalassemias.
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PMID:Laboratory detection of thalassemia. 67 57

Two unrelated families are reported in which beta-thalassemia trait occurred with a heterozygosity of Hb G-Philadelphia (alpha2 68(E17)Asn leads to Lys beta2) in one family and with Hb Rampa (alpha2 95(G2)Pro leads to Ser beta2) in the other. The percentage of Hb G-Philadelphia was not influenced by the simultaneous presence of a beta-thalassemai determinant, but that of Hb Rampa was descreased from 20% in the simple heterozygote to about 6% in persons with the Hb Rampa-beta-thalassemia combination. Data from in vitro recombination experiments with isolated alpha X, alpha A, and beta A chains, with heme attached, indicated a preferential formation of Hb A over Hb Rampa but not over Hb G-Philadelphia in conditions of relative beta-chain deficiency. This suggests that the rate of assembly of monomers to form dimers or tetramers can be an important mechanism of controlling the quantity of certain hemoglobin variants with critical substitutions in heterozygotes.
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PMID:Variability in the interaction of beta-thalassemia with the alpha-chain variants Hb G-Philadelphia and Hb Rampa. 68 17

The influence of malaria on the hemoglobin A2 (Hb A2) level in humans was studied in a series of 94 imported cases in Belgium. Sixty-nine of the patients were natives of Western European countries, their results are reported separately since their origin and the results of their hematological examination made it unlikely that they carried the beta-thalassemia trait. The Hb A2 level of the 94 malaria patients (mean 2.76%; S.D. 0.51%) was not statistically different from that found in 60 healthy controls (mean 2.70%; S.D. 0.38%; P greater than 40). Likewise the level of the 65 Western European patients was not statistically different from that of the same controls (mean 2.81%; S.D. 0.42%; P greater than 0.10). There was also no significant difference between the level in patients infected with a particular species of Plasmodium and that of the controls. No correlation was found between the Hb A2 level and the intensity of the parasitemia or the concentration of total hemoglobin in the blood. These results are discussed in comparison with the divergent ones obtained by others and it is suggested that malaria has no significant influence on the results of surveys for the prevalence of beta-thalassemia in regions of malaria endemicity.
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PMID:Hemoglobin A2 levels in malaria patients. 68 38

In this study the clinical and hematological characteristics, the transmission pattern and the relative rates of globin chain synthesis were determined in the members of four Sardinian families with 14 patients affected by hemoglobin H disease. The severity of hemoglobin H disease in Sardinian subjects shows a high degree of variability. Clinically it usually appears intermediate between the hemoglobin H disease found in Oriental and Negro populations. The alpha/beta specific activity ratio was 0.42 +/- 0.10 indicating an analogous biochemical defect like that described in the Chinese. On the basis of hematological data and alpha/beta ratio, the genetics of hemoglobin H disease in Sardinians seem to follow a pattern similar to that observed in Orientals: one parent showing alpha-thalassemia-1 trait and the other alpha-thalassemia-2 trait. Parent offspring transmission of hemoglobin H disease did occur in 2 out of 6 hemoglobin H matings with spouses carrying the alpha-thalassemia-1 gene. This observation indicates either a high frequency of alpha-thalassemia trait in Sardinians or a high incidence of inbreeding. In one family the mating of a patient with hemoglobin H disease and a normal person produces 6/6 offspring with alpha-thalassemia-1. The genetic implications of this transmission pattern are discussed.
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PMID:Hemoglobin H disease in Sardinia: phenotypic and genetic observations. 70 Oct 89

The predictive value of a prolonged glycerol lysis time (GLT50) was assessed by analysis of case records of 100 consecutive subjects with values greater than 73 seconds (normal = 26--73 seconds) reported by the clinical laboratory of The New York Hospital. There were 72 cases of hemoglobinopathy: 65 thalassemia trait, four sickle-thalassemia, and one each of Hb D-thalassemia, sickle-C disease, and sickle-cell anemia. Nine of the remaining subjects had iron-deficiency anemia, three had chronic renal disease, and seven had miscellaneous disorders. Four subjects were apparently normal, and in five cases there was insufficient information for a diagnosis. Of 78 patients who had both a prolonged GLT50 and microcytosis, 67 (86%) had thalassemia trait and seven (9%) had iron-deficiency anemia. In 74 patients with GLT50 greater than 100 seconds, thalassemia trait was found 16 times as often as uncomplicated iron-deficiency anemia. All 31 subjects with GLT50 greater than 180 seconds had hemoglobinopahy. A prolonged GLT50 strongly suggests thalassemia trait, especially when greater than 100 seconds or associated with microcytosis.
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PMID:The diagnostic significance of a prolonged erythrocytic glycerol lysis time (GLT50). 70 32

A number of varieties of thalassemia were found to be common in the Vancouver area and in other parts of British Columbia. Of 3117 patients whose blood samples were studied by hemoglobin electrophoresis at the Vancouver General Hospital between Jan 1, 1965 and June 30,1977, 813 had the beta-thalassemia trait, 18 had homozygous beta-thalassemia, 97 had alpha-thalassemia trait, 24 had hemoglobin H disease and 14 had miscellaneous variants. Eight patients had interactions of beta-thalassemia with hemoglobin S,C, D, O arab or Vancouver, and one patient had alpha thalassemia associated with hemoglobin Constant Spring. Twelve other variants were noted. They included hemoglobins B2, E, Q, GHsi Tsou, J Bangkok, British Columbia, KOLN, Lepore, Rampa, Tacoma, St. Claude and an unidentified alpha-chain variant.
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PMID:Hemoglobinopathies in a hospital population in Vancouver. 70 69

On 20 consecutive work days during four weeks, one technologist performed 24 microchromatographic determinations of hemoglobin A2 (Hb A2) by each of four methods: the Efremov procedure requiring Tris/HCl buffer, the original Huisman technique with use of glycine developer, and two commercial test kits in which a modified glycine developer is used. The bloood samples tested were obtained from 12 adults with no hematological abnormality and from 12 beta-thalassemia carriers previously diagnosed by familial and hematologic studies. Results by the first method and the two commercial kits (one from Helena Laboratories and one from Isolab, Inc.) did not differ significantly in precision for either the normal or beta-thalassemia trait samples. For both sample types, the second method yielded larger coefficients of variation than those obtained with the other methods. Moreover, the second method was the only one with which values overlapped for normal samples and samples with above-normal Hb A2 concentrations.
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PMID:Microchromatographic methods for hemoglobin A2 quantitation compared. 71 69

In a cooperative intrastate program based upon experience with sickle-cell anemia screening, the authors explored the feasibility of applying hemoglobin electrophoresis for detection of beta-thalassemia gene carriers. Initially, blood samples collected in capillary tubes were analyzed by cellulose acetate electrophoresis with densitometric quantitation of hemoglobin A2 (Hb A2), followed by selective spectrophotometric quantitation. This approach proved insufficiently specific or reproducible. Follow-up hematologic and family studies of presumptive beta-thalassemia gene carriers indicated that coordinate measurement of erythrocytic indices and Hb A2 values would have discriminated a subpopulation with a high incidence of beta-thalassemia trait more specifically. This approach was tested prospectively by the use of 731 venous blood samples collected in a county with a large population of Mediterranean ancestry. Of 31 individuals (4.2%) with presumptive thalassemia trait, 13 returned for a repeat testing, and the initial results for 11 were confirmed. These findings lend support to an empirical screening sequence suggested by Pearson (erythrocytic indices followed by Hb A2 quantitation), but they also indicate that a significant subpopulation of beta-thalassemia gene carriers with limited phenotypic expression may elude detection in any single-pass approach.
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PMID:Population screening for beta-thalassemia minor. Report of cooperative trials based on two approaches. 72 71


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