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 G6PD 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 glucose-6-phosphate dehydrogenase deficiency.