<prompt> A patient who was given primaquine develops dark coloured urine one day after administration of the drug. The likely diagnosis is -Glucose-6-phosphate dehydrogenase deficiencyGlucose-6-phosphate deficiencyGalactose-6-phosphate dehydrogenase deficiencyGalactose-6-phosphataase deficiency  <response>: Ans. is a i.e., Glucose-6-phosphate dehydrogenase deficiency o Development of dark coloured urine within one day of administration of primaquine suggests the possibility of intravascular hemolysis and hemoglobinuria. Primaquine can cause hemolysis in patients with G6PD deficiency. 