On the other hand, it has been reported that glucose-6-phosphate dehydrogenase (G6PDH) deficiency has a protective effect against the development of NAION because of the reduced ability to esterify and accumulate cholesterol in the arteries in G6PDH-deficient subjects [23, 24]. The gene discussed is H6PD; the disease is hyperinsulinemic hypoglycemia, familial, 4.