G6PD and hyperinsulinemic hypoglycemia, familial, 4: Glucose‐6‐phosphate dehydrogenase (G6PD) deficiency is an X‐linked (Xq28 chromosome) recessive genetic disorder and considered a hereditary predisposition to hemolysis, which is due to the mutations in the G6PD gene (G6PD deficiency is the most common enzyme defect associated in humans with clinical manifestations.1