Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A total of 6,120 Japanese males were screened for glucose-6-phosphate dehydrogenase deficiency (G6PD). Five cases with the deficiency were discovered. Two of them and an additional two cases have the same variant, G6PD Ube, characterized by moderate enzyme deficiency, fast moving enzyme activity on electrophoresis, high Ki Nadph, utilization of substrate analogues, kinetics, pH optima, and stability. This variant was distinguished for G6PD A- and from other Oriental variants by biochemical parameters. Differences in the frequency and type of the variants between southern Asia and Japan, suggest that the Japanese who have been isolated on islands where malaria is not endemic, may have developed their own variant traits.
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PMID:G6PD Ube, a glucose-6-phosphate dehydrogenase variant found in four unrelated Japanese families. 83 72

With more than 300 different variants reported, the human enzyme glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) is one of the most polymorphic proteins known. An estimated 400 million people throughout the world are deficient in G6PD; numerous lines of evidence indicate that this is because female heterozygotes have a selective advantage in malaria infections. The cloning of the G6PD gene has made it possible to clarify the molecular basis underlying this enzyme deficiency and polymorphism.
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PMID:The molecular basis of glucose-6-phosphate dehydrogenase deficiency. 163 57

The human X chromosome-linked gene encoding glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) is known to be highly polymorphic from the biochemical characterization of enzyme variants. The variant A (with enzyme activity in the normal range) and the variant A- (associated with enzyme deficiency) each have a frequency of about 0.2 in several African populations. Two restriction fragment length polymorphisms have also been found in people of African descent, but not in other populations, whereas a silent mutation has been shown to be polymorphic in Mediterranean, Middle Eastern, African, and Indian populations. We report now on two additional polymorphisms that we have detected by sequence analysis, one in intron 7 and one in intron 8. The analysis of 54 African male subjects for the seven polymorphic sites, clustered within 3 kilobases of the G6PD gene, has revealed only 7 of the 128 possible haplotypes, indicating marked linkage disequilibrium. These data have enabled us to suggest an evolutionary pathway for the different mutations, with only a single ambiguity. The mutation underlying the A variant is the most ancient and the mutation underlying the A- variant is the most recent. Since it seems reasonable that the A- allele is subject to positive selection by malaria, whereas the other alleles are neutral, G6PD may lend itself to the analysis of the role of random genetic drift and selection in determining allele frequencies within a single genetic locus in human populations.
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PMID:Polymorphic sites in the African population detected by sequence analysis of the glucose-6-phosphate dehydrogenase gene outline the evolution of the variants A and A-. 192 16

A total of 207 men belonging to Bhuyan, Juanga and Munda tribes and 108 non-tribal residents of Banspal block area of Keonjhar district of Orissa were screened for glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, abnormal haemoglobin and malaria parasite. In the tribal group, G-6-PD enzyme deficiency was observed in 13.52 per cent as compared to 3.70 per cent in non-tribals. No abnormal haemoglobin was detected in the studied population, while 15.87 per cent of individuals were positive for Plasmodium falciparum. An extremely weak association was observed between malaria and G-6-PD deficiency.
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PMID:Prevalence of G-6-PD deficiency in a malaria endemic tribal area of Orissa (India). 207 61

The authors report data on the genetic distribution of thalassaemia and of glucose-6-phosphate dehydrogenase deficiency in the populations of certain Sardinian villages, many of which are not only of great antiquity but have maintained isolation for very long periods and therefore possess the following three requirements for suitability for investigation of the possible interrelationships among malaria, thalassaemia and G-6-PD deficiency: a reasonable degree of ethnic homogeneity, availability of reliable demographic data, and availability of malaria-free populations of adequate size and of ethnic background and genetic isolation similar to those of the malarial populations.Investigations including more than 6000 observations in 52 villages demonstrated a positive correlation between the incidences of thalassaemia and G-6-PD deficiency. It is suggested that the genotype that carries thalassaemia and/or the enzyme deficiency may have a high adaptive value in a malarial environment.It is concluded that there is a need further to investigate human genetic structure and the biological fitness of the principal genotype combinations in both existing environments and those that will result from continued cultural evolution.
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PMID:Population genetics of haemoglobin variants, thalassaemia and glucose-6-phosphate dehydrogenase deficiency, with particular reference to the malaria hypothesis. 529 98

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzymopathy of humans, affects over 400 million people. The geographical correlation of its distribution with the historical endemicity of malaria suggests that this disorder has risen in frequency through natural selection by malaria. However, attempts to confirm that G6PD deficiency is protective in case-control studies of malaria have yielded conflicting results. Hence, for this X-linked disorder, it is unclear whether both male hemizygotes and female heterozygotes are protected or, as frequently suggested, only females. Furthermore, how much protection may be afforded is unknown. Here we report that, in two large case-control studies of over 2,000 African children, the common African form of G6PD deficiency (G6PD A-) is associated with a 46-58% reduction in risk of severe malaria for both female heterozygotes and male hemizygotes. A mathematical model incorporating the measured selective advantage against malaria suggests that a counterbalancing selective disadvantage, associated with this enzyme deficiency, has retarded its rise in frequency in malaria-endemic regions. Although G6PD deficiency is now regarded as a generally benign disorder, in earlier environmental conditions it could have been significantly disadvantageous.
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PMID:Natural selection of hemi- and heterozygotes for G6PD deficiency in Africa by resistance to severe malaria. 2343 53

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is seen at a higher frequency in many national and ethnic groups in areas of current or former malaria endemicity. A screening programme undertaken to evaluate the gene frequencies for this deficiency in the highly inbred South Indian population of Karnataka revealed that of the 5140 neonates screened, 7.8% were G6PD deficient with no correlation between the reported level of inbreeding and enzyme deficiency. An interesting finding was the equal number of male (198) and female (207) individuals, with G6PD activity of less than 3 IU. The possible implications of this finding with regard to the expression of G6PD gene is discussed.
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PMID:An unusual distribution of glucose-6-phosphate dehydrogenase deficiency of south Indian newborn population. 800 21

There were 67.76 million persons belonging to scheduled tribes in about 74 distinct groups in India in 1991, or 7.95% of total population, usually living in remote and ecologically diverse climates and areas. Modern medicine has not been accepted in most tribal areas, where magico-religious health care systems prevail. Health conditions in tribal areas have been described as deficient in sanitary conditions, personal hygiene, and health education. Common diseases are sexually transmitted ones and genetic abnormalities such as sickle cell anemia and Glucose-6 Phosphate Enzyme Deficiency (G-6-PD). Disease incidence for sickle cell anemia has been estimated at more than 19% among 35 tribal population groups. 5 million are estimated to be carriers. G-6-PD shows a genetically carried deficiency in a blood enzyme; persons commonly reject antimalarials, antibiotics, and analgesics. The population estimated to have the deficiency is about 13 million, primarily residing in Madhya Pradesh, Maharashtra, Tamil Nadu, Orissa, and Assam states (15%). The incidence is high in malaria zones. Screening kits are needed by health workers, so that identified people can be tattooed and high risk families counseled accordingly. The Onges, Jarawas, and Shompens of Andaman and Nicobar Islands are facing extinction due to endemic diseases, venereal diseases, and a shortage of women. Health workers need information on the folklore related to health of these and other tribal groups, in order to provide appropriate health and sanitary practices and to document indigenous herbs for medical use. Malnutrition is pervasive among tribals. Deficiencies have been detected in gross amounts of calcium, vitamin A, vitamin C, riboflavin, and animal protein. Southern tribes are known for their caloric and protein deficiencies. Those in rice-eating belts tend to have had higher protein intake. The workload of tribal women is heavy, long, and increasing. Maternal mortality is due to unhygienic conditions and inappropriate tribal practices. Interventions must focus on tribal culture, medical training of indigenous people, a health care delivery system catering to the community needs, and more research.
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PMID:A health profile of tribal India. 1228 63

The aim of this study was to determine the frequency of G6PD deficiency and assess its impact on morbidity, especially anemia, in preschool-aged children in Cambodia. A total of 151 children including 82 boys and 69 girls from the Kandal province near Phnom Penh were studied. Ages ranged from 8 to 69 months. Blood was collected in EDTA-coated tubes. Blood counts were performed with an ABX Micros 60 system and G6PD in red blood cells was measured with a Roche Cobas Mira Plus system using Gamma reagents. G6PD deficiency was found in 14 cases (13.4% of boys and 4.3% of girls). Deficiency was complete in 7.3% of children and partial in 2%. Anemia defined as hemoglobin concentration less than 110 g/l was detected in 29.1% of children. No case of anemia could be attributed to enzyme deficiency since no sign of hemolysis was observed in any of the three children presenting both conditions. Further study is needed on G6PD deficiency in Cambodia including malaria-endemic areas and on the frequency and severity of jaundice due to enzyme deficiency in newborns.
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PMID:[Frequency of G6PD deficiency in a group of preschool-aged children in a centrally located area of Cambodia]. 1561 86

Glucose-6-phosphate dehydrogenase (G6PD) deficiency protects from severe forms of malaria. It is interesting therefore to analyze the molecular basis underlying G6PD deficiency in regions such as the Mediterranean basin where malaria was present for a long time in history. Here we report on the genetic characterization of G6PD deficiency among inhabitants of one Mediterranean region-the Dalmatian region of south Croatia. We analyzed 24 unrelated G6PD-deficient male subjects. Molecular testing revealed several different mutations: G6PD Cosenza 9, G6PD Mediterranean 4, G6PD Seattle 3, G6PD Union 3, and G6PD Cassano 1. Furthermore, we have identified one novel G6PD variant that we named G6PD Split. This variant is caused by a nucleotide change 1442 C-->G leading to the amino acid substitution 481 Pro-->Arg and is characterized by moderate enzyme deficiency (class III variant). This study reveals a higher prevalence (37.5%) of the Cosenza mutation in the Dalmatian region than anywhere else previously investigated and overall shows the considerable molecular heterogeneity underlining G6PD deficiency that can be observed in Mediterranean populations.
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PMID:Characterization of G6PD deficiency in southern Croatia: description of a new variant, G6PD Split. 1614 77


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