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)

Erythrocyte pyruvate kinase (PK) deficiency was first described in Basenjis 20 years ago. Although the approach to diagnosis had not been well established, a screening program to detect heterozygotes was thought to have eliminated PK deficiency from the Basenjis of the United States. Four not closely related Basenjis with severe chronic hemolytic anemia, from various parts of the United States, were studied. Their PCV ranged from 16 to 25% and their reticulocyte count was always above 15%. A progressive osteosclerosis was seen in all of the Basenjis and hepatic failure developed in 2 of them. The erythrocyte intermediary metabolite patterns indicated a glycolytic defect at the PK step. Erythrocyte PK activities were markedly increased in the anemic Basenjis, compared with those of a control group, but the enzyme in these Basenjis had abnormal kinetic properties and was thermolabile. An antibody against R-type PK, the regular erythrocyte PK form, did not neutralize the PK activity of affected Basenjis, and results of electrophoretic studies suggested the expression of M2-type PK, a leukocyte and fetal erythroid PK-type. Clinically healthy heterozygous Basenjis had half-normal R-type PK activity and did not express the M2-type in their erythrocytes. We conclude that severe chronic hemolytic anemia, caused by erythrocyte PK deficiency, and associated osteosclerosis still develop in Basenjis. A definitive diagnosis cannot be reached by simply measuring erythrocyte PK activity; rather, diagnosis requires measurement of glycolytic substrate accumulation and enzyme stability and immunologic or electrophoretic studies of erythrocyte PK.
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PMID:Determination of erythrocyte pyruvate kinase deficiency in Basenjis with chronic hemolytic anemia. 207 75

Pyruvate kinase (PK) is an important enzyme for ATP production in the glycolytic pathway. Deficiency of this enzyme in erythrocytes is characterized by hemolytic anemia. Using in situ hybridization, we have mapped the human liver-type pyruvate kinase gene (PKL) to band q21 of chromosome 1.
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PMID:The human liver-type pyruvate kinase (PKL) gene is on chromosome 1 at band q21. 337 52

Inherited hemolytic anemia due to pyruvate kinase (PK) deficiency is an autosomal recessive disease of the Basenji dog that closely resembles human PK deficiency. Characterization of transcriptional and translational expression of PK isozymes and sequencing of DNA from normal and mutant dogs were performed to identify the genetic defect in Basenji dogs. Measurement of erythrocytic PK activity by ion exchange chromatography, substrate kinetics, immunologic reactivity, and electrophoretic mobility suggests that M2-type PK is the major form of PK activity in erythrocytes of PK-deficient dogs, in contrast to normal dogs having only R-type PK activity. Both R-type and M2-type PK mRNA are detectable in reticulocytes of PK-deficient dogs, suggesting that the aberrant isozyme expression is not due to a failure in the erythroid maturational switch from M2- to R-type isozymes. Nucleotide sequence data from wild-type and mutant R-type PK cDNA identified a single nucleotide deletion, delta C433, in the mutant cDNA. The deduced amino acid sequence predicts a truncated mutant protein devoid of all residues contributing to the catalytic site of the wild-type protein. In the absence of R-type PK activity, there is anomalous compensatory expression of M2-type PK in erythroid cells of PK-deficient Basenjis. The PK-deficient Basenji dog may be valuable in somatic cell gene therapy trials involving manipulation of hematopoietic stem cells.
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PMID:The molecular basis of canine pyruvate kinase deficiency. 752 Mar 91

The dependence of the erythrocyte pyruvate kinase (PK)-catalyzed reaction on the glycolytic intermediates glucose-6-phosphate (Gluc-6-P), 2,3-diphosphoglycerate (2,3-DPG) and the nucleotides ADP and ATP was studied in normal individuals and 14 patients with PK deficiency. The Gluc-6-P concentrations in the erythrocytes are markedly elevated (4- to 6-fold) in 9 patients with severe hemolytic anemia compared to those 5 exhibiting a mild clinical course (up to 2-fold increased). 2,3-DPG is elevated up to 2 times compared to the controls whereas the measured ADP and ATP only slightly deviate from the normal range. Control experiments showed that these elevations of Gluc-6-P and 2,3-DPG do not depend on the number of reticulocytes. In enzyme kinetic terms, Gluc-6-P shifts the Hill coefficient to smaller values, i.e. suppresses the positive cooperativity (sigmoidal reaction kinetics), found in normal and some of the mutant enzymes and shift the noncooperative enzymes of some patients to an enzyme exhibiting negative cooperativity. The negative cooperativity already present in the enzymes of some of the patients suffering from severe hemolytic anemia becomes more pronounced upon addition of Gluc-6-P. Apparently 2,3-DPG acts as an antagonist to Gluc-6-P in increasing the Hill coefficient, i.e. enhancing the positive cooperativity of the normal enzyme. It shifts the hyperbolic patients' enzymes to a sigmoidal reaction type and the enzymes of those patients with negative cooperativity to a hyperbolic type. ADP and ATP show a similar behavior as 2,3-DPG, but additionally inhibit the enzyme at higher concentrations. The influence of all four phosphates on the Michaelis constant varies depending on the type of cooperativity, in some cases increasing and in some cases decreasing K0.5 PEP. With 7 of the patients, all of them with severe clinical course, a genetic analysis of their R-type PK gene was performed and genetic defects have been identified in the coding sequence. The found changes in the amino acid sequence and their corresponding location in the tertiary structure of the PK subunit can satisfactorily explain the alterations of the regulatory properties of the mutant enzymes thus allowing to establish a good correlation between altered structural and functional properties of the deficient enzyme and the severeness of the course of the disease.
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PMID:Erythrocyte pyruvate kinase deficiency. The influence of physiologically important metabolites on the function of normal and defective enzymes. 858 2

Deficiency of the R-type pyruvate kinase (R-PK) causes an autosomal recessive, hereditary, nonspherocytic hemolytic anemia (HNSHA). We screened seven unrelated patients from the south of Italy for the known mutations and found one patient homozygous for the 1529A (R510Q) mutation, two others bearing the 1456T (R486W) mutation, one homozygous and another heterozygous, and two heterozygotes for the 994A mutation (G332S). We also found three novel mutations at the heterozygote status: a G to C transversion in position 1010 (1010C; R337P) and a C to T transition in position 1492 (1492T; R498C), which are missense, and a T to G transversion in position 1523 (1523G; L508Z), which produces a stop codon with a subsequent loss of the C-terminal protein domain. The structural features of R-PK in the mutation-bearing regions were examined. In all cases the mutations altered the local conformation of the enzyme. Both G332S and R337P are in highly conserved sequence regions. In particular, the R337P mutation significantly affects the intersubunit interactions, because it is located in a region subjected to a large conformational change that occurs during the R-->T allosteric transition, which is essential for the enzyme activity. The R486W mutation affects an external pocketlike region, producing only a local conformational change; the R498C mutation changes the interactions among neighbouring residues; the R510Q mutation involves the loss of interdomain interactions that may reduce enzyme stability and activity. Our data also indicate that in patients from Southern Italy, pyruvate kinase deficiency is heterogeneous, the 1529A mutation, which is the most frequent mutation in the U.S. Caucasian population, having a lower frequency.
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PMID:Novel mutations and structural implications in R-type pyruvate kinase-deficient patients from Southern Italy. 948 76

The PK-LR gene has been studied in 12 unrelated patients with red cell pyruvate kinase deficiency and hereditary nonspherocytic haemolytic anaemia (CNSHA). The entire codifying region of the R-type PK gene and the flanking intronic regions were analysed by single-stranded conformation polymorphism (SSCP) followed by direct sequencing of abnormal DNA. 10 different mutations were identified in 22/24 alleles at risk. Eight of these were missense mutations that caused the following single amino acid changes: G514C (172Glu-Gln), G1010A (337Arg-Gln), G1015C (339Asp-Gln), T1070C (357Ile-Thr), C1223T (408Thr-Ile), G1291A (431Ala-Thr), C1456T (486Arg-Trp) and G1595A (532Arg-Gln). Two were nonsense mutations: G721T (241Glu-Stop) and C1675T (559Arg-Stop). 7/22 alleles demonstrated the same C1456 --> T mutation. The study of the polymorphic site at nucleotide (nt) 1705 performed in all cases disclosed a 1705 C/C mutation in 10 and a 1705 A/C mutation in three. This is the first report on the presence of several different L-type PK gene mutations within Spanish population. Furthermore, from the PK gene mutations found, six were unique and not previously described (1015C, 1070C, 1223T, 1291A, 1595A and 1675T) and one (C1456T) seems to be predominant in Spain. Interestingly, no case with the 1529A mutation commonly found in Northern European populations was present here.
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PMID:Molecular characterization of the PK-LR gene in pyruvate kinase deficient Spanish patients. Red Cell Pathology Group of the Spanish Society of Haematology (AEHH). 982 8

Human erythrocyte R-type pyruvate kinase (RPK) deficiency is an autosomal recessive disorder produced by mutations in the PKLR gene, causing chronic nonspherocytic hemolytic anemia. Survival of patients with severe RPK deficiency has been associated with compensatory expression in red blood cells (RBCs) of M2PK, an isoenzyme showing wide tissue distribution. We describe a novel homozygous null mutation of the PKLR gene found in a girl with a prenatal diagnosis of PK deficiency. The mutant PK gene revealed an 11-nucleotide (nt) duplication at exon 8, causing frameshift of the PKLR transcript, predicting a truncated protein inferred to have no catalytic activity. Western blot analysis and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) detected no M2PK expression in the peripheral blood red cell fraction. The expression of mutant RPK mRNA in the RBCs was almost 6 times higher than that detected in a control patient with hereditary spherocytosis. This molecular phenotypic analysis of the null mutation in the PKLR gene provides evidence for a lack of M2PK in the mature RBCs of this patient and suggests that normal red cell functions and survival are achieved through a population of young erythroid cells released into the circulation in response to anemia.
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PMID:Life-threatening nonspherocytic hemolytic anemia in a patient with a null mutation in the PKLR gene and no compensatory PKM gene expression. 1587 Jan 73

Human erythrocyte R-type pyruvate kinase deficiency (PKD) is a disorder caused by mutations in the PKLR gene that produces chronic nonspherocytic hemolytic anemia. Besides periodic blood transfusion and splenectomy, severe cases require bone marrow (BM) transplant, which makes this disease a good candidate for gene therapy. Here, the normal human R-type pyruvate kinase (hRPK) complementary (cDNA) was expressed in hematopoietic stem cells (HSCs) derived from pklr deficient mice, using a retroviral vector system. These mice show a similar red blood cell phenotype to that observed in human PKD. Transduced HSCs were transplanted into myeloablated adult PKD mice or in utero injected into nonconditioned PKD fetuses. In the myeloablated recipients, the hematological manifestations of PKD were completely resolved and normal percentages of late erythroid progenitors, reticulocyte and erythrocyte counts, hemoglobin levels and erythrocyte biochemistry were restored. Corrected cells preserved their rescuing capacity after secondary and tertiary transplant. When corrected cells were in utero transplanted, partial correction of the erythrocyte disease was obtained, although a very low number of corrected cells became engrafted, suggesting a different efficiency of cell therapy applied in utero. Our data suggest that transduction of human RPK cDNA in PKLR mutated HSCs could be an effective strategy in severe cases of PKD.
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PMID:Rescue of pyruvate kinase deficiency in mice by gene therapy using the human isoenzyme. 1975 62