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)

Hereditary elliptocytosis (HE) is a common disorder of erythrocyte shape, occurring especially in individuals of African and Mediterranean ancestry, presumably because elliptocytes confer some resistance to malaria. The principle lesion in HE is mechanical weakness or fragility of the erythrocyte membrane skeleton due to defects in alpha-spectrin, beta-spectrin, or protein 4.1. Numerous mutations have been described in the genes encoding these proteins, including point mutations, gene deletions and insertions, and mRNA processing defects. Several mutations have been identified in a number of individuals on the same genetic background, suggesting a "founder effect." The majority of HE patients are asymptomatic, but some may experience hemolytic anemia, splenomegaly, and intermittent jaundice.
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PMID:Hereditary elliptocytosis: spectrin and protein 4.1R. 1507 91

Hemolysis presents as acute or chronic anemia, reticulocytosis, or jaundice. The diagnosis is established by reticulocytosis, increased unconjugated bilirubin and lactate dehydrogenase, decreased haptoglobin, and peripheral blood smear findings. Premature destruction of erythrocytes occurs intravascularly or extravascularly. The etiologies of hemolysis often are categorized as acquired or hereditary. Common acquired causes of hemolytic anemia are autoimmunity, microangiopathy, and infection. Immune-mediated hemolysis, caused by antierythrocyte antibodies, can be secondary to malignancies, autoimmune disorders, drugs, and transfusion reactions. Microangiopathic hemolytic anemia occurs when the red cell membrane is damaged in circulation, leading to intravascular hemolysis and the appearance of schistocytes. Infectious agents such as malaria and babesiosis invade red blood cells. Disorders of red blood cell enzymes, membranes, and hemoglobin cause hereditary hemolytic anemias. Glucose-6-phosphate dehydrogenase deficiency leads to hemolysis in the presence of oxidative stress. Hereditary spherocytosis is characterized by spherocytes, a family history, and a negative direct antiglobulin test. Sickle cell anemia and thalassemia are hemoglobinopathies characterized by chronic hemolysis.
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PMID:Hemolytic anemia. 1520 94

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the commonest red cell enzymopathy in humans and has an X-linked inheritance. It has been reported from India more than 30 years ago and the prevalence varies from 0-27% in different caste, ethnic and linguistic groups. The major clinical manifestations are drug induced hemolytic anemia, neonatal jaundice and chronic non-spherocytic hemolytic anemia. Individuals with G6PD deficiency have a selective advantage against falciparum malaria. Thirteen biochemically characterized variants have been reported from India. At the molecular level, G6PD Mediterranean is the most common deficient variant in the caste groups whereas, G6PD Orissa is more prevalent among the tribal of India. The third common variant seen in India is G6PD Kerala-Kalyan.
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PMID:Glucose-6-phosphate dehydrogenase deficiency in India. 1522 63

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is common in malaria endemic regions and is estimated to affect more than 400 million people worldwide. Deficient subjects are mostly asymptomatic but clinical manifestations range from neonatal jaundice due to acute hemolytic anemia to chronic non-spherocytic hemolytic anemia. To date, biochemical parameters allowed more than 400 different G6PD variants to be distinguished thereby suggesting a vast genetic heterogeneity. So far, only a small portion of this heterogeneity has been confirmed at the DNA level with the identification of about 90 different point mutations in the G6PD coding sequence. To determine the molecular background of G6PD deficiency in Southeast Asian countries, we conducted molecular analyses of G6PD patients from the Philippines, Malaysia, Singapore, Vietnam and Indonesia. The most prevalent mutation identified differs from country to country, thus suggesting independent mutational events of the G6PD gene.
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PMID:Glucose-6-phosphate dehydrogenase deficiency: molecular heterogeneity in southeast Asian countries. 1590 15

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked red blood cell enzymopathy common in malaria endemic areas. Individuals affected by this disease show a wide variety of clinical signs of acute hemolytic anemia. Mutations of the G6PD gene in the Malay population with G6PD deficiency in Kelantan, a state in North East Malaysia were studied. Ninety-three individuals with G6PD deficiency were subjected to mutation analysis of the G6PD gene using polymerase chain reaction based techniques of multiplex PCR. Of the ninety-three DNA samples studied, molecular defects were identified in 80 cases (86%). Variants were heterogeneous - 28.7% were found to have a G to A nucleotide change at nucleotide 871 of the G6PD gene (G871A), corresponding to G6PD Viangchan. The other major mutations were G6PD Mediterranean, G6PD Vanua Lava, G6PD Coimbra, G6PD Kaiping, G6PD Orissa, G6PD Mahidol, G6PD Canton and G6PD Chatham. These results showed that there are heterogeneous mutations of the G6PD gene associated with G6PD deficiency and that G6PD Viangchan and G6PD Mediterranean account for the main variants in G6PD deficiency among the Malay population in Malaysia.
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PMID:G6PD Viangchan and G6PD Mediterranean are the main variants in G6PD deficiency in the Malay population of Malaysia. 1590 17

Use of antimalarial prophylaxis continues to be routine practice among military personnel returning from areas where malaria is endemic. Primaquine may be used for terminal prophylaxis against Plasmodium ovale and Plasmodium vivax. Serious complications of this regimen are infrequent. We report the occurrence of significant hemolytic anemia for two soldiers returning from Operation Iraqi Freedom. They presented with dark urine, headaches, and classic laboratory findings of hemolysis. Both soldiers were subsequently found to have glucose-6-phosphate dehydrogenase deficiency, and both responded to conservative treatment and cessation of medication. Although this complication is unusual, medical personnel involved in the care of recently returned deployed service members should be alert to its potential occurrence among patients who are receiving antimalarial prophylaxis. This complication could be completely avoided with prescreening of personnel for glucose-6-phosphate dehydrogenase deficiency, as is currently done in the Air Force and Navy, before the use of primaquine.
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PMID:Glucose-6-phosphate dehydrogenase deficiency in two returning Operation Iraqi Freedom soldiers who developed hemolytic anemia while receiving primaquine prophylaxis for malaria. 1591 92

Deficiency of glucose-6-phosphate dehydrogenase (G6PD) causes acute hemolytic anemia triggered by oxidative drugs such as primaquine. It is therefore essential in malaria-endemic areas for malaria patients to be confirmed for their G6PD activity before taking primaquine. The WST-8 method, a newly established screening method for G6PD deficiency, has been demonstrated to be suitable for field conditions, particularly for on-site malaria surveys. Here we report a laboratory evaluation by this method of the reactivity of blood-spotted filters. A time-course experiment was conducted to evaluate the reactivity of blood samples spotted onto 4 types of filter paper, Whatman 31ET Chr (ET), 3MM Chr (3MM), P81, and Advantec No. 2 (AD2). The rank of the relative reaction intensity was ET > 3MM = AD2 > P81. Blood-spotted filters stored at 4 degrees C gradually decreased G6PD reactivity with the passage of storage time, whereas those stored at room temperature rapidly reduced their reactivity. Unexpectedly, saponin supplementation reduced the reactivity of blood-spotted filters. In conclusion, 1) ET is the most suitable filter for the WST-8 method; 2) blood-spotted filters stored in cold condition can be assayed within 14 days, or those stored at room temperature should be tested within 3 days; and 3) reaction mixtures should not contain saponin.
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PMID:Reactivity of blood samples spotted onto filter papers in the WST-8 method for screening of G6PD deficiency. 1668 Jan 90

Haptoglobin (Hp) is an acute phase protein that removes free hemoglobin (Hb) released during hemolysis. Hp has also been shown to be toxic for malaria parasites. alpha(+)-Thalassemia is a hemoglobinopathy that results in subclinical hemolytic anemia. alpha(+)-Thassemia homozygosity confers protection against severe malarial disease by an as yet unidentified mechanism. Hp levels were measured in a serial cross-sectional survey of children in Madang Province, Papua New Guinea (PNG). Hp levels were related to age, Hp genotype, Hb levels, parasitemia, splenomegaly, and alpha(+)-thalassemia genotype. Surprisingly, children who were homozygous for alpha(+) -thalassemia had significantly higher levels of Hp than did heterozygotes, after controlling for relevant confounders. We suggest that this is the result of either reduced mean cell Hb associated with alpha(+) -thalassemia homozygosity or an elevated IL-6-dependent acute phase response.
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PMID:Haptoglobin levels are associated with haptoglobin genotype and alpha+ -Thalassemia in a malaria-endemic area. 1676 May 5

There is lack of information about the relative prevalence of haematological disorders in Yemen and other Middle East countries. The aim of this study was to evaluate the pattern of haematological diseases diagnosed by bone marrow examination in Yemen considering the limited diagnostic facilities. At the referral haematology centre in Yemen, between November 1999 and November 2005, 785 patients >14 years old were evaluated by bone marrow examination. Relevant investigations were performed when needed. A total of 627 patients had haematological disorders other than lymphoma, and their data were analysed. There were 273 females and 354 males. A total of 159 patients had Acute myeloid leukaemia, 75 had acute lymphocytic leukaemia, 87 had chronic myeloid leukaemia, 36 chronic lymphocytic leukaemia, eight had multiple myeloma, 13 myelodysplastic syndromes, seven myelofibrosis, seven polycythaemia vera, three primary thrombocythaemia, two hairy cell leukaemia, two metastases, 36 aplastic anaemia, 29 immune thrombocytopenic purpura (ITP), nine autoimmune haemolytic anaemia, three pernicious anaemia, 65 iron deficiency anaemia, 57 megaloblastic anaemia and malaria, 18 mixed deficiencies, and 11 patients had visceral leishmaniasis. Sex- and age-related distribution of the various disorders was also presented. In conclusion, the leukaemias were the most frequently encountered diagnosis followed by iron deficiency anaemia, megaloblastic anaemia and malaria, aplastic anaemia and ITP respectively. The other haematological disorders were less common. These findings are comparable with that seen in other developing and developed countries.
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PMID:Pattern of haematological diseases diagnosed by bone marrow examination in Yemen: a developing country experience. 1710 90

AcB55, AcB61 and CBA/N-Pk(slc) mice carry loss of function mutations in the erythrocyte specific pyruvate kinase gene (Pklr). In AcB55 and AcB61 (Pklr(I90N)) PK deficiency is protective against blood-stage malaria. The mechanistic basis of protection against malaria is unknown and was studied in these two mutant alleles in vivo. The Pklr(G338D) mutation of the CBA/N-Pk(slc) mutant is shown to be more deleterious than the Pklr(I90N) allele with respect to enzymatic activity and severity of hemolytic anemia, with a more dramatic reduction in the half-life of erythrocytes (increased turnover) in the CBA/N-Pk(slc) mice. The CBA/N-Pk(slc) mice are also shown to be highly resistant to infection with Plasmodium chabaudi AS when compared to CBA/J and CBA/N controls. Resistance to malaria, measured as lower levels of blood-stage replication of P. chabaudi, rapid elimination of infected erythrocytes and increased survival to infection, was greater in the Pklr(G338D) mutant, CBA/N-Pk(slc), than in the Pklr(I90N) mutant strains, AcB55/AcB61. These results strongly suggest a correlation between severity of PK-deficiency and extent of protection against malaria. Additionally, the protective effect is independent of the genetic background on which the Pklr mutations occurred.
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PMID:Pyruvate kinase deficiency: correlation between enzyme activity, extent of hemolytic anemia and protection against malaria in independent mouse mutants. 1746 43


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