An inherited disorder in which a person doesn’t have enough of an enzyme called G6PD that helps red blood cells work the way they should. In glucose-6-phosphate dehydrogenase deficiency, the red blood cells break down when the body is exposed to infection, severe stress, or certain drugs, chemicals, or foods. This may lead to a condition called hemolytic anemia. This disorder is most common in African-American men and in men of Middle Eastern or Mediterranean descent. Also called G6PD deficiency.