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Thirteen variables used in the course of characterization of G6PD variants from forty-one individuals have been submitted to multivariate factorial and cluster analysis. Because of the diagrammatic representation of the analysis, two main findings were made possible. Firstly, the three-dimensional plot of the experimental data gives the advantage of a model of classification which is closely related to the ethnogeographical origin of the subjects, and to the clinical and haematological incidence of the G6PD variants. Secondly, cluster analysis visualizes the distance between the G6PDs examined. In this respect, it was determined that three local original variants associated with acute haemolytic anaemia showed a close relationship and belonged to the same cluster (Gd(-) Toulouse, Gd(-) Muret and Gd(-) Colomiers). Conversely, two non-haemolytic variants (G6PD Luz Saint Sauveur and Lozère) were found to be linked in another remote cluster. The procedure developed in this work promotes a new approach to G6PD characteristics in human genetic studies.

A new case of phosphoglycerate kinase (PGK) deficiency is described. The propositus displayed episodes of rhabdomyolysis crises and acute renal failure but did not exhibit any sign of hemolysis. A severe deficiency in phosphoglycerate kinase was revealed in muscle and was also found in erythrocytes, white cells and platelets. A partial defect in the same enzyme was present in the mother's and the two daughters' erythrocytes, indicating a X-linked recessive genetic transmission of the enzyme defect. In the propositus, erythrocyte ATP concentration was normal, although 2,3-diphosphoglycerate and triose phosphate levels were moderately increased. Lactate production from glucose, in vitro, was close to normal in intact red cells. The partial PGK was characterized by an increased Km for ADP and more especially for ATP, reduced thermostability, and diminished electrophoretic mobility. Lack of this enzyme, which is a key step in the glycolytic process (generation of one molecule of ATP), is thought to be responsible for rhabdomyolysis, a fact that has not been reported previously.

The first South African case of haemolytic anaemia due to erythrocyte pyrimidine 5'-nucleotidase deficiency is reported. The anaemia is characterized by the presence of high erythrocyte pyrimidine nucleotide levels and marked basophilic stippling. The enzyme levels in 20 family members confirm an autosomal recessive mode of inheritance and illustrate the difficulty of diagnosing the carrier state.

Clostridium perfringens septicemia with massive hemolysis is described in an elderly woman with refractory anemia. This case is highly unusual in that (1) the diagnosis was made during life by discovery of the organisms on a routine peripheral blood film, and that (2) phospholipase C activity was detected in the serum.

Two new deficient glucose-phosphate-isomerase (GPI) variants have been described in patients suffering from severe chronic hemolytic anemias. The patients' parents were consanguineous, such that the patients were true homozygotes for the mutated GPI genes. In both cases the main cause of the defect in enzyme activity was molecular instability of the mutated GPI molecules, their catalytic activity being nearly normal. GPI 'Paris' was characterized by a slow electrophoretic migration and, above all, a drastically altered affinity for the substrates glucose-6-phosphate (decreased) and fructose-6-phosphate (increased). GPI 'Enfants malades' exhibited a slightly reduced electrophoretic mobility, an abnormal curve of the activity in function of pH, and an abnormal ratio of maximal velocity in the backward direction (fructose-6-phosphate leads to glucose-6-phosphate) to that in the forward direction (glucose-6-phosphate leads to fructose-6-phosphate). No clear relation could be proved between the kinetic abnormalities of the mutant GPI variants on the one hand and the metabolic changes of the GPI-deficient red cells and the severity of hemolysis on the other. Finally we emphasized the possible role of the impairment of hexosemonophosphate pathway in the reduction of viability of the GPI-deficient red cells.

A severe hemolytic crisis was observed in a 5-year-old boy of Italian origin. Analysis of his hemolysate revealed a hemizygous deficiency of glucose-6-phosphate dehydrogenase (G6PD) and a heterozygous deficiency of glucosephosphate isomerase (GPI). According to the literature this is the fourth family with a combined deficiency of these two enzymes located on different chromosomes. Only the G6PD deficiency seems to be responsible for the hemolytic crisis.

Haemolytic anaemia in a Black South African child was found to be associated with reduced glucosephosphate isomerase activity in the red cells. Apart from the haemolytic anaemia, there was no other clinical evidence of dysfunction. Family studies pointed to an autosomal recessive mode of inheritance, with the symptomatic homozygous propositus having a marked enzyme deficiency and the asymptomatic heterozygotes showing intermediate levels of activity. Biochemical characterization showed that, apart from being thermolabile, the electrophoretic mobility and the kinetic properites of the variant enzyme were similar to those of the normal wild type.

The erythrocytic and liver pyruvate kinases (PK) from a patient with congenital nonspherocytic hemolytic anemia have been studied. In red blood cells, the residual activity, 28% of the normal control, presented normal kinetic properties, instability to heat and urea, and slow electrophoretic mobility. The L-type PK from the patient's liver was characterized by normal activity, kinetic properties, stability to heat and urea, and electrophoretic mobility. The fact that erythrocyte mutant PK may, as in previous reports, or may not be associated, as in the present observation, with molecular abnormalities of the liver PK provides support for the hypothesis of a gene rearrangement compatible with two different tissue-specific mRNAs.

We report a hereditary hemolytic anemia associated with a severe erythrocyte pyrimidine 5'-nucleotidase deficiency in a Spanish family of five members in which the parents are first cousins. Both parents exhibited decreased nucleotidase activity without clinical or hematologic abnormalities. Two children (a male and a female) showed severe pyrimidine 5'-nucleotidase deficiency with hemolytic anemia. The remaining child (a male) showed no signs of the disease. The findings strongly suggest an autosomal recessive mode of inheritance in this enzymopathy. This seems to be the first report of pyrimidine 5'-nucleotidase deficiency in Spain.

Phosphatidylinositol kinase activity was determined in red cell membranes from 85 healthy individuals, 20 patients with hereditary hemolytic anemia and 24 patients with myeloproliferative disorder. Increased activity was found in all ten cases of sickle red disease and seven among ten cases of other hereditary hemolytic anemias. These increases had no correlation with the reticulocyte count nor with the red cell shape. An unexpected decreased activity was found in several cases of myeloproliferative disorders, especially in polycythemia vera, with a negative correlation with the reticulocyte count. The mechanism(s) and significance of the phosphatidylinositol kinase abnormalities in these different groups of diseases remain to determine.

Congenital pyrimidin 5'nucleotidase deficiency manifests as hemolytic anemia with basophilic stippling. In lead poisoning, anemia, basophilic stippling and inhibition of erythrocyte pyrimidin 5' deficiency are also observed. In the present work, we report two cases of hemolytic anemia secondary to congenital deficiency of pyrimidin 5' nucleotidase and another case secondary to lead poisoning. Since 1974, when pyrimidin 5' nucleotidase deficiency was isolated, is known that hemolysis is related to the accumulation of pyrimidin nucleotides within the erythrocytes that behave as metabolic inhibitors. However, the precise metabolic process whose inhibition leads to the shortening of erythrocytes half life has not been elucidated yet.

A patient with unexplained erythrocyte glutathione-S-transferase (GST) deficiency has been detected among 513 unrelated persons with hemolytic anemia. An otherwise healthy adult male, the deficient individual had a mild hemolytic anemia with splenomegaly, indirect hyperbilirubinemia, and cholelithiasis. Because he was adopted and childless, the hereditary nature of the defect could not be established. The residual enzyme activity was only about 15% of mean normal. Depletion of glutathione (GSH) from the cells by 1-chloro-2,4-dinitrobenzene (CDNB), a substrate for GST, was somewhat decreased in the red cells from the patient, suggesting that a functional defect existed. The kinetic properties of the residual enzyme and the ratio of activity to antigenicity were normal. Modest decreases in leukocyte and platelet GST activities were documented. Although a cause-and-effect relationship between the GST deficiency and hemolysis may exist, this cannot be proven in the absence of affected family members.

A phosphoglycerate kinase (PGKase: ATP:3-phosphoglycerate 1-phosphotransferase, EC 2.7.2.3; X chromosome-linked) variant, PGKase-Tokyo, is associated with enzyme deficiency, nonspherocytic hemolytic anemia, and neurological disturbances. Because a sufficient amount of the patient's erythrocytes was not available, the variant enzyme was purified to homogeneity from the cultured lymphoblastoid cells of the patient. The enzyme activity of the variant lymphoblastoid cells was about 16% of that of the normal lymphoblastoid cells. PGKase-Tokyo, compared to the normal enzyme, had a lower specific activity (31% of normal in the backward reaction and 15% of normal in the forward reaction), higher than normal Michaelis constants for ATP and 3-phosphoglycerate, a more acidic pH optimum, and increased thermal instability. Microscale peptide mapping analysis revealed that the structural abnormality of PGKase-Tokyo is a single amino acid substitution from valine to methionine at position 266. Thus, the use of the cultured lymphoblastoid cells is proven to be useful for the study of structural and functional abnormalities of mutant enzymes.

Atypical cases of heritable hemolytic anemia have been noted that conform clinically and biochemically to anemias of the pyruvatekinase (PK)-deficient type, except for the presence of apparently adequate quantities of erythrocyte-PK activity by the usual assay procedure. Investigations of four such anomalous cases, occurring in two unrelated families, are presented. Erythrocytes contained a kinetically aberrant isozyme of pyruvate kinase (PK(2)). Michaelis constants for the pathologic isozyme relative to phosphoenolpyruvate were over 10-fold greater than control values, but no kinetic abnormality was evident for the second substrate, adenosine diphosphate. PK(2) exhibited a pH optimum almost 1 U lower than the wild enzyme form (PK(1)). Significant differences were also evident in the functional stabilities of the isozymes. Leukocytes were unaffected. Family studies revealed paternal heterozygosity for quantitative PK deficiency of the usual type. Clinically normal maternal relatives and some siblings demonstrated intermediate deviations in erythrocyte-PK kinetics and reaction characteristics compatible with coexistence of normal PK(1) and kinetically abnormal PK(2). Hemolytic anemia in the propositi appeared to require simultaneous inheritance of the gene governing PK(2) production and its presumed allele resulting in quantitative PK deficiency. Both genetic defects were traced through three generations, the defective gene in both instances apparently resident on autosomes.A revision of the PK assay technique is suggested, since catalytic inefficiency of PK(2) was manifested only at low substrate concentrations and was therefore undetectable at the relatively high phosphoenolpyruvate levels employed in the conventional assay.