G6PD and hyperinsulinemic hypoglycemia, familial, 4: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most frequent human enzyme defect,308 causing hemolytic anemia upon exposure to certain stresses like infection, fava beans, aspirin etc. As the catalyst in the rate-limiting first step of the PPP which produces NADPH, G6PD deficiency disrupts a major metabolic pathway required to produce NADPH and power anti-ferroptotic defence.