Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hemoglobin E, a beta-chain variant commonly found in Southeast Asian populations, is relatively unfamiliar to American physicians. The hematologic features of 55 patients with hemoglobin E (8 homozygote, 46 heterozygote and 1 genotype E/beta(thal)) are described and compared with previous series. The patients were immigrants from Cambodia, Laos, Thailand and Vietnam. These studies support the association of this beta-globin variant with microcythemia and suggest that it mimics the "thalassemia picture" of microcythemia out of proportion to the degree of anemia. Splenomegaly was not a characteristic. Oxidative hemolysis may occur under conditions that deplete reduced glutathione. The simultaneous presence of the beta-thalassemia trait appears to significantly worsen the prognosis.
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PMID:Hemoglobin E in Indochinese refugees. 714 32

Severe haemolytic anaemia with hyperbilirubinaemia and erythroblastaemia was observed in nine newborn infants belonging to one large family. One infant was still-born, two died shortly after birth, five recorded after receiving one or more exchange transfusions and one improved without transfusional therapy. In four out of six newborns whose bilirubin levels were determined, a mixed hyperbilirubinaemia was found with high concentrations of both free and conjugated bilirubin. At the end of the first year of life the surviving children, although in satisfactory general condition, showed a mild microcytic hypochromic anaemia with decreased red cell osmotic fragility and morphological abnormalities of the erythrocytes consisting of microcytosis, anisopoikilocytosis and target cells. The serum iron levels were normal. The same haematological picture was also present in those parents of the affected children that are members of this family; these adult had normal levels of Hbs A2 and F. Incorporation of [3H]leucine into the globin chains of two adults with this syndrome revealed a reduced beta-chain synthesis (beta/alpha ratio of 0 . 49 and 0 . 53, respectively). In the two infants available for this investigation, reduced gamma-chain production was found shortly after birth. In parallel with the switch from fetal to adult haemoglobin, the deficient gamma-chain production was replaced by a similar reduction of beta-chain synthesis. These results suggested, therefore, a combined deficiency of gamma- and beta-chain production. The normal levels of Hb A2 were compatible with a defective delta-chain synthesis as well. Analysis with restriction enzymes had shown previously a large deletion, comprising gamma and delta genes, in one of the chromosomes of the affected individuals. The same procedure had established that, in spite of the defective beta-chain production, the beta-globin structural gene is intact.
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PMID:Haemolytic disease of the newborn and chronic anaemia induced by gamma beta thalassaemia in a Dutch family. 719 73

Effective gene therapy for the severe hemoglobin (Hb) disorders, sickle-cell anemia and thalassemia, will require an efficient method to transfer, integrate, and express a globin gene in primary erythroid cells. To evaluate recombinant adeno-associated virus (rAAV) for this purpose, we constructed a rAAV vector encoding a human gamma-globin gene (pJM24/vHS432A gamma). Its 4725-nucleotide genome consists of two 180-bp AAV inverted terminal repeats flanking the core elements of hypersensitive sites 2, 3, and 4 from the locus control region of the beta-globin gene cluster, linked to a mutationally marked A gamma-globin gene (A gamma) containing native promoter and RNA processing signals. CD34+ human hematopoietic cells were exposed to rAAV particles at a multiplicity of infection of 500-1000 and cultured in semisolid medium containing several cytokines. A reverse transcriptase polymerase chain reaction assay distinguished mRNA signals derived from transduced and endogenous human gamma-globin genes. Twenty to 40% of human erythroid burst-forming unit-derived colonies expressed the rAAV-transduced A gamma-globin gene at levels 4-71% that of the endogenous gamma-globin genes. The HbF content of pooled control colonies was 26%, whereas HbF was 40% of the total in pooled colonies derived from rAAV transduced progenitors. These data establish that rAAV containing elements from the locus control region linked to a gamma-globin gene are capable of transferring and expressing that gene in primary human hematopoietic cells resulting in a substantial increase in HbF content.
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PMID:Recombinant adeno-associated virus (rAAV)-mediated expression of a human gamma-globin gene in human progenitor-derived erythroid cells. 752 85

Although rapid technical advances have taken place in the diagnosis of beta-thalassemia, still the hematological factors were found to be suitable screening test in areas like Indian subcontinent where a high prevalence of beta-thalassemia trait was observed. Among various thalassemias reported in Asian Indians, beta-thalassemia account for about 80% and is responsible for very high infantile mortality. Despite this, little is known about the hematological status of beta-thalassemias among this ethnic group which is associated with more than five different predominant beta-globin mutation with high frequency and variable number of rare ones. The present study is the first report of hematological status of beta-thalassemia among this ethnic group particularly from Tamil Nadu, Southern India, who are still practising high degree of consanguinity. In the present study, a total number of 364 beta-thalassemics were investigated. This includes 84 cases of homozygous beta-thalassemias and the remaining 280 were heterozygotes. The hematological factors such as red cell indices, hemoglobin F and hemoglobin A2 were assessed. The results revealed a wide spectrum of hematological variables ranging from severe form as that of Mediterranean thalassemias to very mild form of anemia as that of African Negro population.
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PMID:Hematological status of beta-thalassemics in Madras. 752 74

In Africa, the beta-globin gene cluster haplotype may be associated with variation of Hb F levels in subjects with sickle cell anemia (SS). These observations have not yet been conclusively confirmed in SS out of Africa, perhaps because of small sample sizes, the predominance of haplotype heterozygotes, and diverse influences, including gender, upon Hb F levels. We studied 384 adult African-American SS patients (mean age, 31 years) and explored the relationship of gender, beta-globin gene cluster haplotype, and alpha thalassemia to hematological values and Hb F levels. Both haplotype and gender influenced Hb F concentration. In the total sample, Hb F was higher in females than in males (8.2 vs. 6.5%). In 35 males who were either homozygous for the Senegal chromosome or had the Senegal/Benin haplotype, the mean percent Hb F (8.0%) was equivalent to the Hb F level in females with Benin and Bantu haplotypes (approximately 7.5%). Both females and males homozygous for the Senegal haplotype chromosome or with the Senegal/Benin combination had a significant increase in Hb F compared to other groups. In 44 Senegal/Senegal or Senegal/Benin females the Hb F was 10.9%, or 1.0 g/dl, the highest value observed in all primary analysis groups. Preliminary analyses suggested that the presence of a Bantu chromosome blunted the gender-associated difference in Hb F, but Hb F differences between females with the Senegal/Benin haplotype (11.2%) and the Senegal/Bantu haplotype (8.8%) were not statistically significant. Hemoglobin concentrations were higher in males than in females except in subjects with at least one Senegal haplotype chromosome, where hemoglobin levels were equal. As expected, alpha thalassemia reduced the MCV, increased hemoglobin concentration, and lowered reticulocyte counts, regardless of haplotype. Hb F levels were not affected by the presence of alpha thalassemia in any group. We conclude that gender and beta-globin gene cluster haplotype interact significantly in the modulation of Hb F and anemia in adults with SS.
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PMID:Gender and haplotype effects upon hematological manifestations of adult sickle cell anemia. 753 53

Hereditary persistence of fetal hemoglobin (HPFH) has typically been ascribed to mutations in the beta-globin gene cluster. Pharmacologic agents, including the short-chain fatty acid butyrate, have been shown to upregulate fetal and embryonic globin gene expression. In this report we investigate the possibility that metabolic derangements characterized by an inability to metabolize another short-chain fatty acid, propionate, could be associated with a persistence of fetal hemoglobin unrelated to alterations in the beta-globin cluster. Embryonic globin gene upregulation in a murine adult erythroid cell culture was shown by RNase protection after induction with three short-chain fatty acids (C2-C5). Chart reviews and measurement of fetal hemoglobin in five patients with abnormalities in propionate (C3) metabolism were undertaken; SSCP/dideoxy fingerprint analysis of the gamma-globin gene promoters was done in three of these five patients. Twelve patients with other metabolic derangements served as controls. Only the four patients with clinically severe abnormalities in propionate metabolism (ages 2 to 11), but without anemia, showed a sustained elevation in fetal hemoglobin (3% to 10%). The level of elevation of fetal hemoglobin in these patients, who lack erythropoietic stress, suggests that propionic acid and/or its metabolites are potent stimulators of fetal hemoglobin expression. Study of this group of patients should allow unique insights into the long-term effects of sustained exposure to elevations of short-chain fatty acid levels.
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PMID:Metabolic persistence of fetal hemoglobin. 753 84

A severely unstable hemoglobin variant, Hb Hakkari or alpha 2 beta 2 31 (B13)Leu-->Arg, has been observed in a 5-year-old Turkish girl with a severe hemolytic anemia without Heinz body formation. A modest increase in liver and spleen size was present and the level of Hb F was a high 33%. The variant could not be observed in red cells and was only detected through sequencing of the amplified beta-globin gene and also by hybridization with specific oligonucleotide probes. The parents were normal, and it is assumed that the variant occurred as a de novo mutation. Smears from bone marrow aspirates showed numerous inclusion bodies in the erythroblast and, as a result, a erythroid hyperplasia. It is suggested that the hemoglobin variant which is unstable and is readily losing its heme group because one of the heme binding sites has been lost, precipitates in the erythroblasts, thus interfering with the maturation process and causing the severe anemia.
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PMID:Hb Hakkari or alpha 2 beta 2 31(B13)Leu-->Arg, a severely unstable hemoglobin variant associated with numerous intra-erythroblastic inclusions and erythroid hyperplasia of the bone marrow. 755 72

An autosomally transmitted hypochromic microcytic mild anaemia with elevated haemoglobin (Hb) A2 and globin chain imbalance has been observed in a three-generation family of Portuguese origin. Extensive DNA analysis of the beta-globin gene cluster, including the complete sequencing of the beta-globin gene and flanking regions, failed to reveal any genetic alteration. The co-segregation of sickle-cell trait in this family enabled us to postulate a defective erythroid trans-acting factor was playing a role in the down-regulation of both beta A- and beta S-globin genes. Among the transcription factors that could possibly have caused the reported phenotype, NF-E2 is unlikely to be implicated, whereas Nrf1 and Nrf2 cannot be ruled out. Thus, this family carries a novel beta-thalassaemia autosomal determinant unlinked to the beta-globin gene. This observation reinforces the notion of the haemoglobinopathies as single gene disorders under polygenic regulation.
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PMID:Beta-thalassaemia unlinked to the beta-globin gene interacts with sickle-cell trait in a Portuguese family. 757 58

The thalassemias are a heterogeneous group of disorders characterized by accumulation either of unmatched alpha or beta globin chains. These in turn cause the intramedullary and peripheral hemolysis that leads to varying anemia. A partial explanation for the hemolysis came our of our studies on material properties that showed that beta-thalassemia (beta-thal) intermedia ghosts were very rigid but unstable. A clue to this instability came from the observation that the spectrin/band 3 ratio was low in red blood cells (RBCs) of splenectomized beta-thal intermedia patients. The possible explanations for the apparent decrease in spectrin content included deficient or defective spectrin synthesis in thalassemic erythroid precursors or globin chain-induced membrane changes that lead to spectrin dissociation from the membrane during ghost preparation. To explore the latter alternative, samples from different thalassemic variants were obtained, ie, beta-thal intermedia, HbE/beta-thal, HbH (alpha-thal-1/alpha-thal-2), HbH/Constant Spring (CS), and homozygous HbCS/CS. We searched for the presence of spectrin in the first lysate of the standard ghost preparation. Normal individuals and patients with autoimmune hemolytic anemia, sickle cell anemia, and anemia due to chemotherapy served as controls. Using gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, no spectrin was detected in identical aliquots of the supernatants of normals and these control samples. Varying amounts of spectrin were detected in the first lysate supernatants of almost all thalassemic patients. The identification of spectrin was confirmed by Western blotting using an affinity-purified, monospecific, rabbit polyclonal antispectrin antibody. Relative amounts of spectrin detected were as follows in decreasing order: splenectomized beta-thal intermedia including HbE/beta-thal; HbCS/CS; nonsplenectomized beta-thal intermedia, HbH/CS; and, lastly, HbH. These findings were generally confirmed when we used an enzyme-linked immunosorbent assay technique to measure spectrin in the first lysate. Subsequent analyses showed that small amounts of actin and band 4.1 also appeared in lysates of thalassemic RBCs. Therefore, the three major membrane skeletal proteins are, to a varying degree, unstably attached in severe thalassemia. From these studies we could postulate that membrane association of abnormal or partially oxidized alpha-globin chains has a more deleterious effect on the membrane skeleton than do beta-globin chains.
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PMID:The instability of the membrane skeleton in thalassemic red blood cells. 757 65

Hb Lulu Island [beta 107(G9)Gly-->Asp] was discovered in an East Indian female who carried a common beta zero-thalassemia allele, i.e., codon 15, TGG-->TAG (is a stop codon) in trans. Both abnormalities were detected through sequencing of the amplified beta-globin genes and were confirmed by hybridization with 32P-labeled probes. Hb Lulu Island is mildly unstable with a borderline decrease in oxygen affinity; its instability is less severe than that of Hb Burke or beta 107(G9)Gly-->Arg. The compound heterozygosity expresses as a thalassemia intermedia with moderate anemia, a variable need for blood transfusions, Heinz body formation, and a red cell morphology which is typical for such a condition. The level of HbA2 was greatly increased (6.5-7.0%) as was the delta chain level (12% of total non-alpha) probably because of the instability of Hb Lulu Island and the decreased ability of the beta x chain to form dimers with the normal alpha chain.
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PMID:Hb Lulu Island (alpha 2 beta 2 107[G9]Gly-->Asp)-beta zero- thalassemia (codon 15; TGG-->TAG), a form of thalassemia intermedia. 766 21


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