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)

The metabolic changes of red blood cells from 25 patients with chronic hemolytic anemia caused by G6PD deficiency were investigated. The average G6PD activity exhibited 5 per cent of the normal control. The glucose oxidation was in most cases reduced even by 50 per cent. Three groups could be distinguished according to their degree of methylene blue stimulation of the oxidative pentose phosphate pathway. These results are in agreement with changes of the kinetic constants for NADP, NADPH and G6P, respectively. The filtrability of red blood cells decreased in all cases of G6PD deficiency but no correlation was found with the survival time. First results of a preventive medication with D-L-alpha-tocopherol let assume a reduction of chronic hemolysis.
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PMID:Metabolism of the hexose monophosphate shunt in glucose-6-phosphate dehydrogenase deficiency and closely interrelated reactions. 718 79

A new variant of G6PD associated with chronic non-spherocytic haemolytic anaemia (CNSHA) in an Irish male is described. This variant is unique in that it has a normal electrophoretic mobility, Michaelis constant for G6P and NADP, and a normal pH optimum, together with a marked increase in utilisation of the substrate 2 deoxy glucose-6-phosphate. It is also relatively heat stable when compared with the normal (B) variant. These characteristics distinguish this variant from previously reported variants associated with CNSHA and we have called it G6PD Dublin.
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PMID:G6PD (Dublin): chronic non-spherocytic haemolytic anaemia resulting from glucose-6-phosphate dehydrogenase deficiency in an Irish kindred. 740 Nov 30

A new variant of G6PD with total enzyme deficiency associated with nonspherocytic hemolytic anemia in a 60 year old Frenchman is characterized. Partially purified enzyme revealed slow electrophoretic mobility, decreased G6P affinity, thermal instability, abnormal pH curve with a single peak at pH 5.0, abnormal utilization of 2-deoxy-G6P and deamino NADP. This variant differs from all previously reported variants associated with chronic nonspherocytic hemolytic anemia. Accordingly this variant is designated Gd(-) Rennes.
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PMID:Gd(-) Rennes, a new deficient variant of glucose-6-phosphate dehydrogenase associated with congenital nonspherocytic hemolytic anemia found in France. 745 Jul 48

Glucose 6-phosphate dehydrogenase (G6PD) plays a key role in the generation of NADPH which is essential for maintaining glutathione in the reduce state, and in the production of ribose 5-phosphate for the synthesis of nucleotides. G6PD in its active form is either a dimer or tetramer consisting identical subunits. The gene for G6PD is located on the X chromosome. Human red cell G6PD consists of 515 amino acids with a molecular weight of 59,265 daltons. Deficiency of G6PD is the most common metabolic disorder, and is associated with chronic and drug- or infection-induced hemolytic anemia. It is estimated that 400 million people in the world are affected. The mutations responsible for about 73 variants have been determined. Some of them have polymorphic frequencies in different populations. Except for seven kinds of variants with small gene deletion, splice site deletion of intron or three nucleotide substitutions, all of those were found to be produced by one or two nucleotide substitutions. Molecular studies disclosed that all the class 1 variants associated with chronic hemolysis have the mutations surrounding either the substrate or the NADP binding site.
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PMID:[Glucose-6-phosphate dehydrogenase]. 760 82

In the course of molecular studies on Japanese glucose-6-phosphate dehydrogenase (G6PD) variants using single-strand conformation polymorphisms (SSCP) analysis, we found an unusual class 1 G6PD variant that had nucleotide deletion in exon 9. The patient showed chronic nonspherocytic hemolytic anemia associated with frequent episodes of severe hemolytic attack. The hemolysate exhibited no measurable activity. Although the partially purified enzyme had detectable activity, we could not perform kinetic studies because of its extreme instability. Nucleotide sequencing showed a unique 24 bp deletion at nucleotide 953-976 that predicts an eight amino acid deletion of TKGYLDDP at residue 319-326. While this is one of the most drastic structural alterations found in G6PD variants, the region with the amino acid deletion was distant from both the G6P and NADP+ binding sites and was located in a domain with low sequence homology among species. The comparatively low functional importance of the deleted region may have saved the patient from lethal tissue dysfunction.
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PMID:G6PD Nara: a new class 1 glucose-6-phosphate dehydrogenase variant with an eight amino acid deletion. 824 97

Molecular abnormalities of erythroenzymopathies associated with hereditary hemolytic anemia have been determined by means of molecular biology. Pyruvate kinase (PK) deficiency is the most common and well-characterized enzyme deficiency in the glycolytic pathway, and it causes hereditary hemolytic anemia. To date, 47 gene mutations have been identified. We identified one base deletion, one splicing mutation, and six distinct missense mutations in 12 unrelated families with a homozygous PK deficiency. Mutations located near the substrate or fructose-1,6- diphosphate binding site may change the conformation of the active site, resulting in a drastic loss of activity and severe clinical symptoms. Glucose-6-phosphate dehydrogenase (G6PD)deficiency is the most common metabolic disorder, and it is associated with chronic hemolytic anemia and/or drug- or infection-induced acute hemolytic attack. An estimated 400 million people are affected worldwide. The mutations responsible for about 78 variants have been determined. Some have polymorphic frequencies in different populations. Most variants are produced by one or two nucleotide substitutions. Molecular studies have disclosed that most of the class 1 G6PD variants associated with chronic hemolysis have the mutations surrounding either the substrate or the NADP binding site. Among rare enzymopathies, missense mutations have been determined in deficiencies of glucosephosphate isomerase, (TPI), phosphoglycerate kinase, and adenylate kinase. Compound heterozygosity with missense mutation and base deletion has been determined in deficiencies of hexokinase and diphosphoglyceromutase. Compound heterozygosity with missense and nonsense mutations has been identified in TPI deficiency. One base junction mutations resulting in abnormally spliced PFK-M mRNA have been identified in homozygous PFK deficiency. An exception is hemolytic anemia due to increased adenosine deaminase activity. The basic abnormality appears to result from the overproduction of a structurally normal enzyme.
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PMID:Molecular basis of erythroenzymopathies associated with hereditary hemolytic anemia: tabulation of mutant enzymes. 857 52

The molecular abnormalities of erythroenzymopathies associated with hereditary hemolytic anemia have been determined using molecular techniques. Pyruvate kinase (PK) deficiency is the most common and well-characterized enzyme deficiency involving the glycolytic pathway and causing hereditary hemolytic anemia. We have identified six distinct missense mutations and a form of splicing mutation in 11 unrelated families with homozygous PK deficiency. Mutations located near the substrate binding site may change the conformation of the active site, resulting in a drastic loss of activity and severe clinical symptoms. Up to now, including these genetic defects, 21 missense, 1 nonsense and 2 splicing mutations, 2 insertions, and 3 deletions have been determined. G6PD deficiency is the most common metabolic disorder, and is associated with chronic and drug- or infection-induced hemolytic anemia. To date, sixty different mutations have now been identified. Except for three kinds of variants with small gene deletions or three nucleotide substitutions, all of those were found to be produced by one or two nucleotide substitutions. Molecular studies disclosed that all the class 1 variants associated with chronic hemolysis have the mutations surrounding either the substrate or the NADP binding site. Among rare enzymopathies, missense mutations have been determined in glucosephosphate isomerase deficiency, aldolase deficiency, triosephosphate isomerase (TPI) deficiency, phosphoglycerate kinase deficiency, and adenylate kinase deficiency. Compound heterozygous cases with missense mutation/nonsense mutation and missense mutation/decreased mRNA have been reported in TPI deficiency and diphosphoglyceromutase deficiency, respectively. In phosphofructokinase (PFK) deficiency, three kinds of 5'-splice junction mutations resulting in abnormally spliced PFK-M mRNA were identified. An exception is a hemolytic anemia due to increased adenosine deaminase activity. The basic abnormality appears to result from overproduction of structurally normal enzyme.
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PMID:Red cell enzymopathies as a model of inborn errors of metabolism. 862 88

We have investigated the blood cells from a woman with a low degree of chronic nonspherocytic hemolytic anemia and frequent bacterial infections accompanied by icterus and anemia. The activity of glucose 6-phosphate dehydrogenase (G6PD) in her red blood cells (RBCs) was below detection level, and in her leukocytes less than 3% of normal. In cultured skin fibroblasts, G6PD activity was approximately 15% of normal, with 4- to 5-fold increased Michaelis constant (Km) for NADP and for glucose 6-phosphate. Activated neutrophils showed a decreased respiratory burst. Family studies showed normal G6PD activity in the RBCs from all family members, including both parents and the 2 daughters of the patient. Sequencing of polymerase chain reaction (PCR)-amplified genomic DNA showed a novel, heterozygous 514C-->T mutation, predicting a Pro172-->Ser replacement. Analysis of G6PD RNA from the patient's leukocytes and fibroblasts showed only transcripts with the 514C-->T mutation. This was explained by the pattern of X-chromosome inactivation, studied by means of the human androgen receptor (HUMARA) assay, which proved to be skewed in the patient, her mother, and one of the patient's daughters. Thus, the patient has inherited a de novo mutation in G6PD from her father and an X-chromosome inactivation determinant from her mother, causing exclusive expression of the mutated G6PD allele. Purified mutant protein from an Escherichia coli expression system showed strongly decreased specific activity, increased Km for NADP and for glucose 6-phosphate, and increased heat lability, which indicates that the defective phenotype is due to 2 synergistic molecular dysfunctions: decreased catalytic efficiency and protein instability.
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PMID:Molecular basis and enzymatic properties of glucose 6-phosphate dehydrogenase volendam, leading to chronic nonspherocytic anemia, granulocyte dysfunction, and increased susceptibility to infections. 1055 77

As many as one-third of mutations in a gene result in the corresponding enzyme having an increased Michaelis constant, or K(m), (decreased binding affinity) for a coenzyme, resulting in a lower rate of reaction. About 50 human genetic dis-eases due to defective enzymes can be remedied or ameliorated by the administration of high doses of the vitamin component of the corresponding coenzyme, which at least partially restores enzymatic activity. Several single-nucleotide polymorphisms, in which the variant amino acid reduces coenzyme binding and thus enzymatic activity, are likely to be remediable by raising cellular concentrations of the cofactor through high-dose vitamin therapy. Some examples include the alanine-to-valine substitution at codon 222 (Ala222-->Val) [DNA: C-to-T substitution at nucleo-tide 677 (677C-->T)] in methylenetetrahydrofolate reductase (NADPH) and the cofactor FAD (in relation to cardiovascular disease, migraines, and rages), the Pro187-->Ser (DNA: 609C-->T) mutation in NAD(P):quinone oxidoreductase 1 [NAD(P)H dehy-drogenase (quinone)] and FAD (in relation to cancer), the Ala44-->Gly (DNA: 131C-->G) mutation in glucose-6-phosphate 1-dehydrogenase and NADP (in relation to favism and hemolytic anemia), and the Glu487-->Lys mutation (present in one-half of Asians) in aldehyde dehydrogenase (NAD + ) and NAD (in relation to alcohol intolerance, Alzheimer disease, and cancer).
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PMID:High-dose vitamin therapy stimulates variant enzymes with decreased coenzyme binding affinity (increased K(m)): relevance to genetic disease and polymorphisms. 1191 49

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzymopathy. Human G6PD gene is highly polymorphic, with over 130 mutations identified, many of which cause hemolytic anemia. We studied a novel point mutation in the G6PD gene 1226 C-->G, predicting the proline 409 to arginine substitution (G6PD Suwalki). We expressed the human wild-type and mutated G6PD gene in yeast Saccharomyces cerevisiae which allowed the characterization of the Suwalki variant. We showed that human wild-type, as well as the mutated (1226 C-->G) G6PD gene, functionally complemented the phenotype displayed by the yeast strain with disruption of the ZWF1 gene (homologue of the human G6PD gene). Comparison of wild-type (wt) human G6PD purified from yeast and from blood shows no significant differences in the Km values for G6P and in the utilization rate for the substrate analogue, 2-deoxyG6P. The P409R substitution leads to drastic changes in G6PD kinetics. The specific activity as well as stability of mutated G6PD is also significantly reduced. Besides this, the effect of this mutation was analyzed using a model of the tertiary structure of the human enzyme. The localization of the P409R mutation suggests that it may influence the stability of the whole protein by changing tetramer interactions and disturbing the binding of structural NADP+.
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PMID:A novel mutation in the glucose-6-phosphate dehydrogenase gene in a subject with chronic nonspherocytic hemolytic anemia--characterization of enzyme using yeast expression system and molecular modeling. 1475 26


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