Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002878 (hemolytic anemia)
 7,530 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

G6PD deficiency is a common hemolytic genetic disorder, particularly in the areas endemic to malaria. Individuals are generally asymptomatic and hemolytic anemia occurs when some anti-malarial drugs or other oxidizing chemicals are administered. It has been proposed that G6PD deficiency provides protection against malaria. Maintaining of G6PD deficient alleles at polymorphic proportions is complicated because of the X-linked nature of G6PD deficiency. A comprehensive review of the literature on the hypothesis of malarial protection and the nature of the selection is being presented. Most of the epidemiological, in vitro and in vivo studies report selection for G6PD deficiency. Analysis of the G6PD gene also reveals that G6PD-deficient alleles show some signatures of selection. However, the question of how this polymorphism is being maintained remains unresolved because the selection/fitness coefficients for the different genotypes in the two sexes have not been established. Prevalence of G6PD deficiency in Indian caste and tribal populations and the different variants reported has also been reviewed.
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PMID:Present status of understanding on the G6PD deficiency and natural selection. 1769 98

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect, being present in more than 400 million people worldwide. The global distribution of this disorder is remarkably similar to that of malaria, lending support to the so-called malaria protection hypothesis. G6PD deficiency is an X-linked, hereditary genetic defect due to mutations in the G6PD gene, which cause functional variants with many biochemical and clinical phenotypes. About 140 mutations have been described: most are single base changes, leading to aminoacid substitutions. The most frequent clinical manifestations of G6PD deficiency are neonatal jaundice, and acute haemolytic anaemia, which is usually triggered by an exogenous agent. Some G6PD variants cause chronic haemolysis, leading to congenital non-spherocytic haemolytic anaemia. The most effective management of G6PD deficiency is to prevent haemolysis by avoiding oxidative stress. Screening programmes for the disorder are undertaken, depending on the prevalence of G6PD deficiency in a particular community.
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PMID:Glucose-6-phosphate dehydrogenase deficiency. 1875 69

Several studies have suggested that T cell-producing permeability factors might lead to proteinuria in minimal change nephrotic syndrome (MCNS). However, it is still unclear whether T-cell abnormalities cause MCNS. Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare disorder of the immune regulation system, which leads to severe autoimmune phenomena including autoimmune enteropathy, atopic dermatitis with high levels of serum immunoglobulin E (IgE), type 1 diabetes mellitus (T1DM), and severe infection such as sepsis, which frequently result in death within the first 2 years of life. This disease is caused by mutations in the FOXP3 gene that result in the defective development of regulatory T (Treg) cells. This report describes a 5-year-old boy with IPEX syndrome with a 3 bp deletion in the FOXP3 gene (c.748-750delAAG, p.250K.del) and a paucity of CD4(+) CD25(+) FOXP3(+) T cells. The boy's condition was complicated by MCNS in addition to many IPEX-related manifestations, such as atopic dermatitis, T1DM, enteropathy, sepsis and hemolytic anemia. This is the first report of IPEX syndrome complicated by MCNS, and our findings imply that Treg cell dysfunction may be crucial for the development of MCNS.
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PMID:Minimal change nephrotic syndrome associated with immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome. 1918 34

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a typical X-linked enzymopathy causing severe haemolytic anaemia in males, and mild to moderate anaemia in homozygous females. Haemolysis due to G6PD deficiency in patients with type 1 diabetes mellitus (T1DM) has been principally reported in males, but is uncommon. During the last 10 years 2 girls with an unknown incomplete G-6-PD deficiency showed haemolysis during the treatment of DKA at the onset of T1DM. We speculate that the patients here described showed haemolytic anaemia as a phenotypic expression of the lyonization process and/or an uncommon penetrance of the defective gene. Haemolysis occurred when blood glucose levels were returning to normal values. In normal red blood cells, G6PD provides a source of reducing power for maintaining sulphydryl groups (SH) and facilitating the detoxification of free radicals and peroxides. During insulin i.v. infusion the copious glucose available due to the hyperglycaemia progressively decreased and affected the old red blood cells to generate nicotinamide adenine dinucleotide (NADPH), a crucial source for energy-dependent functions. This NADPH loss could have enhanced the rate of all factors such as methaemoglobin generation, Heinz body formation, and lipid peroxidation, which occur in G6PD deficient cells in response to both endogenous and exogenous oxidants. The direct consequence of this phenomenon is an increased erytrocyte oxidant sensitivity and a loss of sulphydryl group availability causing premature red blood cell destruction.
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PMID:Haemolysis during diabetic ketoacidosis treatment in two girls with incomplete glucose-6-phosphate dehydrogenase deficiency. 1970 24

Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal non-malignant hematological disease characterized by the expansion of hematopoietic stem cells (HSCs) and progeny mature cells, whose surfaces lack all the proteins linked through the glycosyl-phosphatidyl inositol anchor. This defect arises from an acquired somatic mutation in the X-linked phosphatidylinositol glycan class A gene, with subsequent clonal expansion of the mutated HSCs as a result of a concomitant, likely immune-mediated, selective pressure. The disease is characterized by complement-mediated chronic intravascular hemolysis, resulting in hemolytic anemia and hemosiderinuria; capricious exacerbations lead to recurrent gross hemoglobinuria. Additional cardinal manifestations of PNH are a variable degree of bone marrow failure and an intrinsic propensity to thromboembolic events. The disease is markedly invalidating, with chronic symptoms requiring supportive therapy - usually including periodical transfusions; possible life-threatening complications may also ensue. The biology of PNH has been progressively elucidated in the past few years, but therapeutic strategies remained unsatisfactory for decades, the only exception being stem cell transplantation, which is restricted to selected patients and retains significant morbidity and mortality. Recently, a biological agent to treat PNH has been developed - the terminal complement inhibitor eculizumab - which has been tested in a number of clinical trials, with exciting results. All the data from worldwide clinical trials confirm that eculizumab radically modifies the symptoms, the biology, and the natural history of PNH, strongly improving the quality of life of PNH patients.
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PMID:Paroxysmal nocturnal hemoglobinuria: pathophysiology, natural history and treatment options in the era of biological agents. 1970 55

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common form of red blood cell enzymopathy. The disorder has reached polymorphic frequencies in different parts of the world due to the relative protection conferred against malaria. G6PD is a housekeeping X-linked gene encoding the first enzyme of the pentose phosphate pathway, an NADPH-producing dehydrogenase. Because erythrocytes do not generate NADPH in any other way than pentose phosphate pathway, they are more susceptible than any other cells to oxidative damages. G6PD deficiency is a prime example of a hemolytic anemia due to an interaction between an intracorpuscular cause and an extracorpuscular cause, because in the majority of cases an exogenous agent triggers hemolysis. Hemolysis, in fact, can be caused by exposure to oxidant agents. Although studies performed on epidemiology, genetics and molecular biology have broaden the information on G6pd deficiency, there are still no reliable and validated methods to test drug hemolytic potential in G6PD deficient patients. The review gives an overview of current knowledge on G6pd deficiency and on the methods that have been developed so far in order to identify drugs causing acute hemolytic anemia in G6pd deficiency. Moreover, we discuss the new potential preclinical strategies to assess, in vitro and in vivo, drug hemolytic risks.
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PMID:Discussion on pharmacogenetic interaction in G6PD deficiency and methods to identify potential hemolytic drugs. 2035 Feb 85

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, an X-linked disorder, is usually observed in hemizygote males and very rarely in females. The G6PD class 1 variants, very uncommon, are associated with chronic hemolytic anemia. Here we report a Portuguese woman who suffered in her sixties from a chronic hemolytic anemia due to G6PD deficiency. Molecular studies revealed heterozygosity for an in-frame 18-bp deletion, mapping to exon 10 leading to a deletion of 6 residues, 362-367 (LNERKA), which is a novel G6PD class 1 variant, G6PD Tondela. Two of her three daughters, asymptomatic, with G6PD activity within the normal range, are heterozygous for the same deletion. The patient's leukocyte and reticulocyte mRNA studies revealed an almost exclusive expression of the mutant allele, explaining the chronic hemolytic anemia. Patient whole blood genomic DNA HUMARA assay showed a balanced pattern of X chromosome inactivation (XCI), but granulocyte DNA showed extensive skewing, harboring the mutated allele, implying that in whole blood, lymphocyte DNA, with a very long lifetime, may cover up the current high XCI skewing. This observation indicates that HUMARA assay in women should be assessed in granulocytes and not in total leukocytes.
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PMID:Chronic hemolytic anemia is associated with a new glucose-6-phosphate dehydrogenase in-frame deletion in an older woman. 2139 31

Glucose-6-phosphate dehydrogenase (G6PD), an X-linked hereditary deficiency, is the most common of all clinically significant enzyme defects. While many drugs are responsible for haemolytic anaemia in G6PD-deficient patients, acetaminophen's imputability is still under debate, although an overdose of this drug can provoke acute haemolytic events. We report a case of a Philipino child carrying the G6PD-Vanua Lava mutation with acute haemolytic crisis related to infection in progress and acetaminophen's administration. Fever and concomitant infection, through an increment of erythrocyte glutathione depletion, sensitized the infant to the haemolytic event. In this condition, acetaminophen (or paracetamol [PCM]) was capable of inducing a haemolytic crisis in our G6PD-deficient patient although administered under standard conditions. PCM seems to have induced the haemolytic event, probably by the alteration of its catabolism due to dehydration and fever. The enzymatic G6PD instability associated to the presence of the G6PD-Vanua Lava mutation could have led to an increment of red blood cells' sensitivity to lysis; hence, it is possible that PCM toxicity may also be due to the presence of this particular mutation. Finally, we propose a new biochemical classification of this G6PD variant.
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PMID:Acute haemolytic crisis due to concomitant presence of infection and possible altered acetaminophen catabolism in a Philipino child carrying the G6PD-Vanua Lava mutation. 2144 92

Phosphoglycerate kinase (PGK) catalyzes an important ATP-generating step in glycolysis. PGK1 deficiency is an uncommon X-linked inherited disorder, generally characterized by various combinations of non-spherocytic hemolytic anemia, neurological dysfunctions, and myopathies. Patients rarely exhibit all three clinical features. To provide a molecular framework to the different pathological manifestations, all known mutations were reviewed and 16 mutant enzymes, obtained as recombinant forms, were functionally and structurally characterized. Most mutations heavily affect thermal stability and to a different extent catalytic efficiency, in line with the remarkably low PGK activity clinically observed in the patients. Mutations grossly impairing protein stability, but moderately affecting kinetic properties (p.I47N, p.L89P, p.C316R, p.S320N, and p.A354P) present the most homogeneous correlation with the clinical phenotype. Patients carrying these mutations display hemolytic anemia and neurological disorders, and,except for p.A354P variant, no myopaty. Variants highly perturbed in both catalytic efficiency (p.G158V, p.D164V, p.K191del, D285V, p.D315N, and p.T378P) and heat stability (all, but p.T378P) result to be mainly associated with myopathy alone. Finally, mutations faintly affecting molecular properties (p.R206P, p.E252A, p.I253T, p.V266M, and p.D268N) correlate with a wide spectrum of clinical symptoms. These are the first studies that correlate the clinical symptoms with the molecular properties of the mutant enzymes. All findings indicate that the different clinical manifestations associated with PGK1 deficiency chiefly depend on the distinctive type of perturbations caused by mutations in the PGK1 gene, highlighting the need for determination of the molecular properties of PGK variants to assist in prognosis and genetic counseling. However, the clinical symptoms can not be understood only on the bases of molecular properties of the mutant enzyme. Different (environmental, metabolic, genetic and/or epigenetic) intervening factors can contribute toward the expression of PGK deficient clinical phenotypes.
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PMID:Molecular insights on pathogenic effects of mutations causing phosphoglycerate kinase deficiency. 2234 48

The XG blood group system is best known for its contributions to the fields of genetics and chromosome mapping. This system comprises two antigens, Xg(a) and CD99, that are not antithetical but that demonstrate a unique phenotypic relationship. XG is located on the tip of the short arm of the X chromosome with exons 1 to 3 present in the pseudoautosomal region of the X (and Y) chromosome(s) and exons 4 to 10 located only on the X chromosome. Xg(a) demonstrates a clear X-linked pattern of inheritance. MIC2, the gene encoding the CD99 antigen, is found in the pseudoautosomal region of both the X and Y chromosomes. Anti-Xg(a) is comparatively rare, and only two examples of anti-CD99 have ever been identified. Alloanti-Xg(a) is considered clinically insignificant; only one example of autoanti-Xg(a) has been reported, but it resulted in severe hemolytic anemia. Insufficient data exist to determine the clinical significance of anti-CD99. Linkage of XG to several X-borne genes encoding inherited disorders has been demonstrated. CD99 is an adhesion molecule, and high levels are associated with some types of cancer.
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PMID:XG: the forgotten blood group system. 2235 23


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