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)

A Turkish family is described in which three children have a clinical picture similar to that of thalassemia major, with typical red cell morphology and indices, and with about 10% Hb Bart's but without measurable amounts of Hb H. Hematological evaluation of six members of this family that included in vitro hemoglobin synthesis suggests that beta-(or delta beta-) thalassemia, beta-silent thalassemia, and mild and severe alpha-thalassemia genes are present in different combinations. The data indicate that beta/alpha chain ratios in patients with more than one type of thalassemia should be evaluated in relationship to values obtained for several relatives even though some of the thalassemia determinants may be silent in the parents.
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PMID:alpha-Thalassemia and beta-thalassemia in a Turkish family. 86 64

Hematology results from 3800 blood samples were examined for the presence of erythrocytic microcytosis. One hundred patients with electronically measured mean corpuscular volumes of 75 cubic microns or less were reviewed to determine the cause of microcytosis and evaluate recently described simplified techniques for separating thalassemia trait from other causes of microcytosis. The discriminant function formula of England and Fraser [MCV - RBC - (5 x Hgb) - 3.4] was found to be useful in uncomplicated patients with the Mediterranean type of thalassemia trait (betadegree) but less useful in the African type (beta+) of heterozygous beta-thalassemia. Anemias of chronic disorders were found to be a major cause of microcytosis. Microcytosis of no apparent cause was found in some children. Improved techniques in hemoglobin A2 quantification remain the best approach for detecting beta-thalassemia heterozygotes.
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PMID:Erythrocytic microcytosis: clinical implications in 100 patients. 87 Nov 34

The wide range of globin synthesis ratios reported in patients with sickle cell disease casts doubt on whether the presence of genes for alpha- or beta-thalassemia in combination with Hb S can be detected by globin synthesis studies. We have studied globin synthesis in 20 patients with Hb SS who had a mean betaA/alpha ratio of 1.05+/-0.04, similar to that of 28 control children. In nine of these patients the percentage of newly synthesized radioactive alpha-chains in dimer or monomer forms was 16.3%+/-1.3, also similar to the control subjects. The remainder of alpha-chain was in hemoglobin tetramer. In nine patients with Hb SC, the (non-alpha)/alpha ratio was 0.97+/-0.04, and the free alpha-chain pool radioactivity in four patients was 14.1%+/-4.2. In three patients with Hb CC, betac/alpha ratios were 0.99, 1.07, and 1.10. These results indicate that globin synthesis ratios and alpha-chain radioactivity in the free alpha-chain pool of peripheral blood of patients with Hb SS, Hb SC, and Hb CC have narrow ranges, close to those of nonthalassemic controls. The data provide a basis for detecting syndromes with Hb S or Hb C associated with alpha- or beta-thalassemia. This precise differentiation is important for clinical studies of severity in sickle cell disease and for genetic counseling.
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PMID:Globin biosynthesis in sickle cell, Hb SC, and Hb C diseases. 87 50

beta-Thalassemia is a major public health problem in Algeria. During a survey, a family including two cases of betaO-thalassemia was studied. The family study indicated that two of the affected siblings had homozygous beta-thalassemia; there were also both normal and heterozygous siblings, and both parents had beta-thalassemia trait. In the two cases of betaO-thalassemia there was no hemoglobin A in the peripheral blood, and no beta-globin chain synthesis in whole cell incubations. Hybridization of purified complementary DNA specific for alpha- and beta-globin messenger RNAs demonstrated less than 1% mRNAbeta relative to mRNAalpha in circulating reticulocytes, and for one case in total RNA from bone marrow. There is no apparent beta-globin gene deletion as determined by hybridization in globin cDNAbeta sequence excess. Therefore the Algerian cases studied are similar in molecular pathology to some Southern Italian and Asian cases described previously, and differ from other Italian and Chinese betaO-thalassemias, in which hybridizable mRNAbeta has been demonstrated, and from deltabetaO-thalassemia, which is caused by a gene deletion.
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PMID:beta-O-thalassemia from Algeria: genetic and molecular characterization. 88 23

Glutathione peroxidase (GSHPx) activity was found to be greatly elevated in members of a family with alpha-thalassemia. Eleven other families with proven alpha-thalassemia were investigated, and all but one subject with hemoglobin H disease had increased red cell GSHPx. Most persons with alpha-thalassemia trait also had increased activity of red cell GSHPx. In contrast, only very modest increases in glutathione peroxidase activity were observed in subjects with various forms of beta-thalassemia.
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PMID:Increased glutathione peroxidase activity in alpha-thalassemia. 90 38

The T gamma chain of human fetal hemoglobin has a threonyl in stead of an isoleucyl residue in position 75. When the cord bloods from infants from varied ethnic backgrouds and geographic areas were tested for the presence of the T gamma chain, it was present in 28 or 98 samples. In some groups as many as 40% had the T gamma chain whereas none was detected in other. When the T gamma chain was present, its quantity was about 20% of the total gamma chains, but one case had 35%. Among beta-thalassemia homozygotes of the Mediterranean region, 70% and the T gamma chain in the amount of 20-50% of the total gamma chains, but seven Black beta-thalassemia homozygotes were negative for the T gamma chain. The fetal hemoglobin of 16 adult patients with sickle cell anemia had no T gamma chains, but 2 of 9 newborn children with sickle cell anemia had the T gamma chain. The frequency of the T gamma gene (16), the relationship of the T gamma gene to the G gamma and A gamma genes, and the significance of the T gamma gene are discussed.
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PMID:The T gamma chain of human fetal hemoglobin at birth and in several abnormal hematologic conditions. 90 75

The molecular defect that has been demonstrated in alpha-thalassemia is the deletion of the alpha-globin structural genes. Since thalassemias are composed of heterogeneous groups of disorders, other types of defects could also result in alpha-thalassemia. We studied a Chinese family in which analysis of the mode of inheritance of alpha-thalassemia-1 and hemoglobin-H disease suggests a lesion that is not due to structural-gene deletion. Molecular hybridization studies with synthetic radioactive DNA's complementary to alpha-globin mRNA sequences show that in addition to the usual deletion defect, a nondeletion defect produces the phenotype of alpha-thalassemia-1. The combination of the deletion and non-deletion defects results in hemoglobin-H disease and not homozygous alpha-thalassemia associated with hydrops fetalis.
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PMID:Identification of a nondeletion defect in alpha-thalassemia. 90 65

Molecular hybridization with synthetic radioactive DNA (cDNA) complementry to alpha globin mRNA sequences shows that, as in most other Southeast Asian populations, the alpha globin structural genes are deleted in Filipinos affected by the alpha-thalassemia syndromes. Thus, all 4 alpha-globin structural genes are deleted in homozygous alpha-thalassemia with hydrops fetalis, 3 and 2 structural genes are deleted in hemoglobin H disease and alpha-thalassemia-1 respectively.
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PMID:The molecular defects of alpha-thalassemia in the Filipino. 91 35

Three new families providing information on the linkage relationships between the delta and beta hemoglobin loci are reported. One of the families contains the first reported individuals having Hb S and Hb B2 in coupling. Analysis of the information found in the literture is compatible with a recombination frequency of 3 percent between beta thalassemia and the delta structural locus. This highly improbable frequency might be explained by either diagnostic errors or paternity problems in the pedigrees containing recombinants or by the conceivable possibility that certain thalassemia genes increase the probability for recombination in the chromosomal region containing the non alpha globin genes.
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PMID:The linkage relationships of the beta and delta hemoglobin genes. 91 37

A 25 year old woman with congenital dyserythropoietic anemia (CDA) Type I is described. Typical morphologic abnormalities of the erythroid precursors in the bone marrow by light and electron microscopy, marked ineffective erythropoiesis and iron loading were present, Globin chain synthetic ratios as well as functional and structural studies on the patients hemoglobin were normal, ruling out the presence of thalassemia or a mutant hemoglobin which can both give rise to morphologic and clinical features similar to CDA. The laboratory findings on this patient and family members and a brief review of the literature are presented.
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PMID:Biosynthetic and structural studies of hemoglobin in a patient with congenital dyserythropoietic anemia type I. 91 41


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