G6PD hillbrow: a new variant of glucose-6-phosphate dehydrogenase associated with drug-induced haemolytic anaemia.
A new genetic variant of the red cell enzyme glucose-6-phosphate dehydrogenase is described. It was observed in a patient presenting with severe haemolytic anaemia and renal failure following ingestion of an overdose of Beserol (paracetamol and chlormezanone). The enzyme in the red cell had 12% of the activity of a normal B+ control, but only slightly lower activity in the kidney compared with a normal control. The red cell enzyme showed normal electrophoretic mobility and thermostability, a biphasic pH optimum curve, higher than normal utilization of the substrate analogues 2-deoxy-glucose-6-phosphate and deamino-NADP, and lower than normal Michaelis constants for both substrates, glucose-6-phosphate and NADP. The enzyme was strongly inhibited in vitro by high concentrations of paracetamol and chlormezanone. The extent of inhibition was similar to that for the enzyme from a normal B+ individual.
D000082:Acetaminophen / Q000494:pharmacology; D000328:Adult; D000743:Anemia, Hemolytic / Q000139:chemically induced*; D002110:Caffeine; D002328:Carisoprodol; D002720:Chlormezanone / Q000494:pharmacology; D004008:Diclofenac; D004338:Drug Combinations; D004905:Erythrocyte Aging / Q000187:drug effects; D004912:Erythrocytes / Q000201:enzymology; D014644:Genetic Variation; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors / Q000097:blood* / Q000302:isolation & purification; D006801:Humans; D008297:Male
D004338:Drug Combinations; C011407:acetaminophen, caffeine, carisoprodol, diclofenac drug combination; D004008:Diclofenac; D002328:Carisoprodol; D000082:Acetaminophen; D002110:Caffeine; D005954:Glucosephosphate Dehydrogenase; D002720:Chlormezanone