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)

In this study, we carried out restriction endonuclease mapping in order to characterize the alpha-globin genotype of 10 Sardinian beta 0-thalassemia heterozygotes, all of whom presented with normal red blood cell indices and increased HbA2 levels. In 8 of these subjects, we found the deletion of two alpha-globin genes (-alpha/-alpha), and in the remaining two the deletion of a single alpha-globin gene (-alpha/alpha alpha). In three of these carriers with the (-alpha/-alpha) alpha-globin genotype and in one with the (-alpha/alpha alpha) genotype, we also found the glucose-6-phosphate dehydrogenase (G6PD) defect of the Mediterranean type. On the basis of these findings, we may conclude that the interaction of heterozygous beta 0-thalassemia with alpha-thalassemia, due to the deletion of either one or two alpha-globin genes, may lead to the production of red blood cells with normal indices. The association of the G6PD defect with this thalassemia gene complex may eventually contribute to this effect. We suggest, therefore, that screening programs for heterozygous beta-thalassemia in populations where alpha-thalassemia is also prevalent, should incorporate the determination of HbA2 in the first set of tests.
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PMID:Phenotypic effect of heterozygous alpha and beta 0-thalassemia interaction. 630 42

It is suggested here that a Hemoglobin S (HbS)-mediated membrane oxidant injury is responsible for both the protection from malaria infection in the heterozygous sickle cell state, and for a critical pathologic process in homozygous sickle cell disease. This suggestion is arrived at by applying to the HbS condition the oxidant stress model for malaria resistance. Such a model had been developed to explain the protection from malaria in thalassemia and in glucose-6-phosphate dehydrogenase (G6PD) deficiency (9).
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PMID:Hemoglobin S-mediated membrane oxidant injury: protection from malaria and pathology in sickle cell disease. 647 60

Genetic markers have recently been found to be much more polymorphic than expected. Such extensive human polymorphisms may be partly explained by a number of genetic and environmental factors, including infectious diseases. Malaria, which was very widespread in the past and still poses a problem in many countries today, is a good candidate for research. The association between malaria and glucose-6-phosphate dehydrogenase (G6PD) deficiency is well-known, but more should be done to determine the mechanisms responsible for this positive correlation and to confirm that malaria is a strong selective factor for many other genotypes also. The present paper refers to a WHO project on genetic markers and susceptibility to infectious diseases, which is concerned mainly with G6PD deficiency and the following genetic markers: haemoglobinopathies, including the beta-thalassaemia trait and ABO, Rh, MN, Duffy, secretory types (Ss), and human leukocyte antigens (HLA). Since malaria was eradicated in Bulgaria many years ago, human populations from this country, living at different altitudes above sea-level, were used as a model for analysis of the malaria hypothesis. The data for G6PD deficiency confirm that malaria was a selective factor in lowland areas where malaria infection was more frequent in the past. It is, moreover, apparent that in addition to malaria some other factors also play a selective role.
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PMID:Frequency of glucose-6-phosphate dehydrogenase deficiency in relation to altitude: a malaria hypothesis. 696 37

The study reports results of investigations on hemoglobin, pseudocholinesterase, Australia antigen and glucose-6-phosphate dehydrogenase in 153 mental retardates and 161 controls. beta-thalassemia and the hemoglobin phenotype AS occurred more in patients. At the pseudocholinesterase locus, the patients had significantly higher frequencies of E1a and E1f (p less than 0.001). Mental retardation was found to be associated also with presence of Australia antigen and with G-6-PD deficiency. A model to explain these findings has been proposed.
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PMID:Biochemical genetics and mental retardation: a study of hemoglobins, Australia antigen and the enzymes pseudocholinesterase and glucose-6-phosphate dehydrogenase. 727 94

Haemoglobin variants, beta-thalassaemia and glucose-6-phosphate dehydrogenase (G-6-PD) types were studied in 702 individuals from Buchanan, Liberia. In this population haemoglobins S and C, beta-thalassaemia and G-6-PD deficiency were found together. There was a considerable tribal variation. In the tribes of eastern Liberia the S- and C-genes were uncommon and the beta-thalassaemia gene was rather frequent, while in western Liberia the S- and C-genes were more frequent and beta-thalassaemia uncommon. In the central and northern parts the S- and beta-thalassaemia genes were found together in relatively high frequencies. The rate of malaria infection was found to be lower in individuals with the sickle cell and beta-thalassaemia traits than in individuals with haemoglobin AA, but the difference was not statistically significant. The frequency of the delta-chain gene B2 was 1.4% in the total material and there was no significant tribal variation for this gene. The frequency of G-6-PD deficiency estimated in males was 16%.
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PMID:Haemoglobin variants, beta-thalassaemia and G-6-PD types in Liberia. 733 23

In Saudi Arabia two major forms of sickle cell anaemia (SCA) have been identified, a benign SCA is reported mainly in the Eastern province and a severe form is reported in other parts of the country. Multiple factors including associated alpha-thalassaemia, elevated Hb F and glucose-6-phosphate dehydrogenase (G-6PD) deficiency have often been reported as modifying the clinical presentation of the disease. However, these factors do not completely explain the amelioration in the clinical manifestations in SCA. More recently interest has been directed toward the investigations of the regions surrounding the beta-globin genes. Using restriction endonucleases extensive polymorphism has been identified and different haplotypes have been encountered. We initiated studies in the different regions of Saudi Arabia. Our studies on the Saudi population from different regions of the country using Hinc II and Hind III showed that the beta-globin gene haplotype ++-++ is associated with a mild sickle cell anaemia, while ----+ is associated with the severe form of the disease. Xmn I polymorphic site 5' to the G gamma gene and 7.6 kb Hpa I fragments 3' to the beta-globin gene are also associated mainly with the mild disease. This paper presents and compares the two major forms of SCA in Saudi population and relates it to the genetic heterogeneity.
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PMID:The relationship of the genetic heterogeneity of sickle cell gene to clinical manifestations. 809 5

In order to develop a rational and early detection of combined forms of hemoglobin and enzymopathies, 1500 samples of neonatal cord blood were tested for alpha- and beta-thalassemia, of abnormal hemoglobins S and C, of methemoglobinemia and for hereditary persistence of fetal hemoglobin as well as 428 samples were examined for glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and glutathione reductase (EC 1.6.4.2) deficiencies. For this purpose, isoelectrofocusing in Multiphor-2117 polyacrylamide-ampholine plates (LKB, Sweden) at pN 3.5-9.5 and pH 5.5-8.5 was carried out with subsequent laser densitometry of gels (Densitometer 2202, LKB). The data obtained were analyzed simultaneously in biochemical, hematological and genealogical studies. Hereditary impairments detected were evidenced by genealogical analysis.
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PMID:[Detection of combined forms of hemoglobino- and enzymopathies in newborns]. 830 76

We studied 41 patients with beta-thalassaemia major and their parents by using a combination of polymerase chain reaction (PCR) amplification, slot-blot hybridization of allele-specific oligonucleotide (ASO), and direct genomic sequencing. Eight different point mutations were characterized. C to T substitution at nucleotide (nt) 654 of intervening sequences (IVS) 2, accounting for 46.3% of mutant beta-globin genes, is the most common mutation in Taiwan, followed by frameshift codons 41/42 with four nucleotides (TCTT) deletion for 31.7%, A to G substitution at position -28 of promotor area for 8.5%, A to T substitution at codon 17 for 6.1%, frameshift codons 27/28 (insertion of C) for 2.4%, G to T substitution at nucleotide 1 of IVS-1 for 2.4%, frameshift codons 71/72 (insertion of A) and IVS-1 3 end TAG-->GAG for 1.2%. The former four mutations showed no obvious difference between two major ethnic groups in Taiwan. As to mutations in each individual of beta-thalassaemia major, the incidence of compound heterozygotes of two different mutations is much higher than homozygotes of single mutation, 78.0% v 22.0%. Compound heterozygotes of C to T substitution at nt 654 of IVS-2 and frameshift codons 41/42 with four nucleotides deletion is the most common pattern of beta-thalassaemia mutations in each individual (41.5%). The results are somewhat different from other documented reports concerning the mutations of beta-thalassaemia in southern China. This is the first report of mutation of IVS-1 3' end TAG-->GAG which causes consensus change in Chinese people. Patients with heterozygotes of beta zero and -28 beta(+)-thalassaemia mutations would have a greater delay in initial transfusion in comparison to patients with homozygotes of both beta zero-thalassaemia mutation, but their initial clinical manifestation might be aggravated when combined with a glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and an insult such as exposure to infection and certain drugs.
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PMID:Molecular basis and haematological characterization of beta-thalassaemia major in Taiwan, with a mutation of IVS-1 3' end TAG-->GAG in a Chinese patient. 843 18

A countrywide prospective study aimed at establishing the prevalence of the haemoglobinopathy genes in the Portuguese population was carried out by screening 15,208 randomly selected blood samples from young males. This male based survey provided the opportunity of assessing simultaneously the prevalence of the red cell enzyme glucose-6-phosphate dehydrogenase (G6PD) deficiency, thus giving a picture of these important hereditary anaemias in Portugal. The results showed a low average frequency of beta thalassaemia (0.45%) and haemoglobin S (0.32%) carriers as well as G6PD deficiency (0.51%). However, these disorders are unevenly distributed throughout the country with a higher prevalence in some areas, mainly in the south. The relationship of this pattern of haemoglobinopathies to the known haplotypes linked to beta thalassaemia and sickle cell disease, relevant historical events, and local selective pressure was investigated. Hb D and Hb J are the commonest other structural variants. The implemented programme for control of these hereditary anaemias is described.
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PMID:Hereditary anaemias in Portugal: epidemiology, public health significance, and control. 847 8

The Jews of Kurdistan are a small inbred population with a high incidence of beta-thalassaemia and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Recently, it was reported that the beta-thalassaemia in this population shows an unusual mutational diversity; 13 different mutations were identified, of which 4 had not previously been observed in any other population. In contrast, we now report that the G6PD deficiency, which has the highest known incidence in the world, and which affects about 70% of males, is almost entirely attributable to a single widespread mutation, G6PD Mediterranean.
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PMID:G6PD Mediterranean accounts for the high prevalence of G6PD deficiency in Kurdish Jews. 847 15


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