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)

To develop new treatments for beta-thalassemia, it is essential to identify the genes involved in the relevant pathophysiological processes. Iron metabolism in thalassemia mice being investigated, focusing on the expression of a gene called hepcidin (Hamp), which is expressed in the liver and whose product (Hamp) is secreted into the bloodstream. In mice, iron overload leads to overexpression of Hamp, while Hamp-knockout mice suffer from hemochromatosis. The aim of this study is to investigate Hamp in the mouse model of beta-thalassemia and to address the potential gene transfer of Hamp to prevent abnormal iron absorption.
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PMID:Exploring the role of hepcidin, an antimicrobial and iron regulatory peptide, in increased iron absorption in beta-thalassemia. 1633 90

In recent years, there have been growing expectations about the future benefits deriving from the uptake of genetics knowledge in healthcare. At the same time, there have been increasing calls to make greater use of patient expertise in treatment. However, relatively little is known about the experiences, needs and expertise of those who currently have a genetic condition. Drawing on the findings from an Australian study involving 21 semi-structured interviews with members of support groups which represent those with various genetic conditions (cystic fibrosis, haemochromatosis, haemophilia, and thalassaemia) this article discusses how individuals learn about, live with and manage their condition, and assesses the extent to which their experiences differ from those with other chronic illness conditions. It argues that while the experiences of individuals who have a genetic condition would appear to be similar in many respects to those with other chronic illnesses, they tend to encounter particular challenges in managing their condition due to its inheritable nature.
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PMID:The best experts: the narratives of those who have a genetic condition. 1643 Oct 6

Recent advances in molecular genetics have led to a better understanding of hereditary iron overload syndromes, of which the most frequent are recessive HFE-hemochromatosis and, to a much lesser extent, dominant ferroportin disease. Acquired iron overload syndromes can be related to metabolic syndrome (insulin resistance syndrome), end-stage cirrhosis, or hematological disorders such as thalassemia and refractory anaemia.
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PMID:[Human hepatic iron overload syndromes]. 1673 93

A range of iron binding dendrimers terminated with hexadentate ligands formed from hydroxypyridinone, hydroxypyranone, and catechol moieties have been synthesized in order to investigate their potential as clinically useful iron(III)-selective chelators capable of removing dietary iron from the gastrointestinal tract and preventing the development of iron overload typical of haemochromatosis and thalassaemia intermedia. The iron chelating abilities of these molecules have been characterized by MALDI-TOF mass spectrometry and UV spectrometry. Hydroxypyridinone-terminated dendrimers were found to possess a high affinity and selectivity for iron(III). A hydroxypyridinone-based dendrimer was demonstrated to be highly efficient at reducing the absorption of iron(III) in rat intestine. This family of dendrimers may find an application in the treatment of iron overload.
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PMID:Iron binding dendrimers: a novel approach for the treatment of haemochromatosis. 1682 77

Information currently available to the public is inadequate to support those deciding to consent to a genetic test. As genetic knowledge continues to evolve, more people will be forced to consider the complex issues raised by genetic testing. We developed and tested criteria to guide the production and appraisal of information resources produced for the public on genetic testing. Lay people with and without experience of a genetic condition, and providers and producers of health information appraised and listed the criteria they used to rate the quality of a sample of information on cystic fibrosis, Down's syndrome, familial breast cancer, familial colon cancer, haemochromatosis, Huntington's disease, sickle cell disease, and thalassaemia. These genetic conditions represent different populations, disease pathways, and treatment decisions. The information medium could be written, electronic, CD, audio or video. The quality criteria were tested iteratively (using the weighted kappa statistic) for the level of agreement between users applying successive drafts of the criteria to different samples of information. The final set of criteria consisted of 19 questions plus an overall quality rating. Chance corrected agreement (weighted kappa) among the appraisers for the overall quality rating was 0.61 (0.60-0.62). The criteria cover the scope of the information resources, information on the condition, the test procedure and results, decision making, and the reliability of the information. The DISCERN-Genetics criteria will guide the production and appraisal of information produced for the public, and will facilitate the involvement of the public in decisions around genetic screening and testing.
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PMID:DISCERN-Genetics: quality criteria for information on genetic testing. 1686 57

Beta-thalassaemia represents a group of diseases, in which ineffective erythropoiesis is accompanied by iron overload. In a mouse model of beta-thalassaemia, we observed that the liver expressed relatively low levels of hepcidin, which is a key factor in the regulation of iron absorption by the gut and of iron recycling by the reticuloendothelial system. It was hypothesised that, despite the overt iron overload, a putative plasma factor found in beta-thalassaemia might suppress liver hepcidin expression. Sera from beta-thalassaemia and haemochromatosis (C282Y mutation) patients were compared with those of healthy individuals regarding their capacity to induce changes the expression of key genes of iron metabolism in human HepG2 hepatoma cells. Sera from beta-thalassaemia major patients induced a major decrease in hepcidin (HAMP) and lipocalin2 (oncogene 24p3) (LCN2) expression, as well as a moderate decrease in haemojuvelin (HFE2) expression, compared with sera from healthy individuals. A significant correlation was found between the degree of downregulation of HAMP and HFE2 induced by beta-thalassaemia major sera (r = 0.852, P < 0.0009). Decreased HAMP expression was also found in HepG2 cells treated with sera from beta-thalassaemia intermedia patients. In contrast, the majority of sera from hereditary haemochromatosis patients induced an increase in HAMP expression, which correlated with transferrin (Tf) saturation (r = 0.765, P < 0.0099). Our results suggest that, in beta-thalassaemia, serum factors might override the potential effect of iron overload on HAMP expression, thereby providing an explanation for the failure to arrest excessive intestinal iron absorption in these patients.
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PMID:Downregulation of hepcidin and haemojuvelin expression in the hepatocyte cell-line HepG2 induced by thalassaemic sera. 1693 99

A standard aqueous stem bark extract from selected species of Mangifera indica L. (Anacardiaceae)--Vimang, whose major polyphenolic component is mangiferin, displays potent in vitro and in vivo antioxidant activity. The present study provides evidence that the Vimang-Fe(III) mixture is more effective at scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals, as well as in protecting against t-butyl hydroperoxide-induced mitochondrial lipid peroxidation and hypoxia/reoxygenation-induced hepatocytes injury, compared to Vimang alone. Voltammetric assays demonstrated that Vimang, in line with the high mangiferin content of the extract, behaves electrochemically like mangiferin, as well as interacts with Fe(III) in close similarity with mangiferin's interaction with the cation. These results justify the high efficiency of Vimang as an agent protecting from iron-induced oxidative damage. We propose Vimang as a potential therapy against the deleterious action of reactive oxygen species generated during iron-overload, such as that occurring in diseases like beta-thalassemia, Friedreich's ataxia and haemochromatosis.
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PMID:Interaction of Vimang (Mangifera indica L. extract) with Fe(III) improves its antioxidant and cytoprotecting activity. 1700 Jan 17

Hereditary hemochromatosis is a disorder of iron metabolism characterized by increased iron intake and progressive storage and is related to mutations in the HFE gene. Interactions between thalassemia and hemochromatosis may further increase iron overload. The ethnic background of the Brazilian population is heterogeneous and studies analyzing the simultaneous presence of HFE and thalassemia-related mutations have not been carried out. The aim of this study was to evaluate the prevalence of the H63D, S65C and C282Y mutations in the HFE gene among 102 individuals with alpha-thalassemia and 168 beta-thalassemia heterozygotes and to compare them with 173 control individuals without hemoglobinopathies. The allelic frequencies found in these three groups were 0.98, 2.38, and 0.29% for the C282Y mutation, 13.72, 13.70, and 9.54% for the H63D mutation, and 0, 0.60, and 0.87% for the S65C mutation, respectively. The chi-square test for multiple independent individuals indicated a significant difference among groups for the C282Y mutation, which was shown to be significant between the beta-thalassemia heterozygote and the control group by the Fisher exact test (P value = 0.009). The higher frequency of inheritance of the C282Y mutation in the HFE gene among beta-thalassemic patients may contribute to worsen the clinical picture of these individuals. In view of the characteristics of the Brazilian population, the present results emphasize the need to screen for HFE mutations in beta-thalassemia carriers.
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PMID:HFE gene mutations in Brazilian thalassemic patients. 1716 Feb 66

Since the discovery of HFE gene in 1996, considerable progress has been made concerning the iron-metabolism and its major abnormalities. Five types of hereditary hemochromatosis are actually known: type 1 (HFE gene), type 2A (HJV gene), type 2B (HAMP gene), type 3 (TfR2 gene), type 4 (SLC40A1 gene). The HFE C282Y +/+ mutation is responsible for the most frequent type of hemochromatosis in France. Various secondary causes can lead to iron-overload: associated genetic diseases, exogenous iron intake, thalassaemia and refractory anaemia, hepatic siderosis, alcoholic hepatitis, cutaneous porphyria and cirrhosis. The deleterious consequences of iron-overload are due to the interactions of the environmental factors. The role of HFE heterozygote mutations is still discussed. In clinical practice, the interpretation of a serum ferritin increase is a frequent problem that needs a careful evaluation based on the tranferrin saturation measurement. Significant increase of both these factors is in favour of an HFE C282Y +/+ hemochromatosis, after exclusion of a hepatocellular insufficiency or a refractory anaemia. Nevertheless, high ferritin is not always a marker of iron-overload. Thus, there are many disorders increasing the serum ferritin levels without iron overload : cytolysis (hepatic...), inflammatory or infectious syndromes, high alcohol intake, neoplasia... Looking for HFE mutations help to separate type 1 hemochromatosis from other conditions mainly hepatic siderosis (metabolic disorders). The identification of rare types of hemochromatosis (types 2-4) is only required in particular cases. The evaluation of the iron overload is now based on hepatic MRI determination rather than liver biopsy. Repeated phlebotomies remain the essential way to decrease the iron overload in HFE hemochromatosis and to prevent the occurrence of severe and irreversible complications (cirrhosis, arthropathies, cardiac failure, and diabetes). Because of the link established between the amount of iron-overload and the occurrence of complications and the mortality over-risk in HFE C282Y +/+ hemochromatosis, venesections must be started when serum ferritin is higher than 300 microg/l in man and 200 microg/l in woman, whatever the clinical manifestations are and obviously before the symptomatic phase of the disease.
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PMID:[Hereditary and acquired iron overload]. 1737 75

Iron overload is a well-documented complication in thalassemia intermedia. Moreover, it is seen that the number of blood transfusions received does not correlate with the degree of overload. Since, HFE gene is associated with iron overload; the present study was conducted in an attempt to evaluate its role in thalassemia intermedia. The subjects were consecutive thalassemia intermedia cases attending the Hematology outpatient clinic. Controls were healthy hospital staff with negative family history of hemolytic anemia or liver disease. The molecular analysis for HFE mutations H63D and C282Y were done with primers described earlier. ELISA was used to measure serum ferritin. Sixty-three patients of thalassemia intermedia including 48 beta-homozygous/heterozygous thalassemia intermedia and 15 HbE-beta-thalassemia were studied. Six (12.5%) of the former and two (13.3%) of the latter were heterozygous for H63D; one of which, a 51-year old male also had clinical features of hemochromatosis. In healthy controls, prevalence of H63D heterozygosity was 7.5% (6/80). An interesting feature observed was that though the age and transfusions taken were similar in both groups, the serum ferritin greater than 500 ng/dl were observed in all patients (100%) with HFE mutation whereas it was seen in 12/42 (28.6 %) of patients without the mutation (p = 0.002). Thus, it is concluded that thalassemia intermedia patients with co-existent HFE mutation have a higher likelihood of developing iron overload and may require early iron chelation.
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PMID:HFE mutation H63D predicts risk of iron over load in thalassemia intermedia irrespective of blood transfusions. 1747 69


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