Favism: A condition characterized by hemolytic anemia (breakup of red blood cells) after eating fava beans (Vicia fava) or being exposed to the pollen of the fava plant. This dangerous reaction occurs exclusively in people with a deficiency of the enzyme glucose-6-phosphate dehydrogenase (G6PD), an X-linked genetic trait. However, not all G6PD-deficient families appear at risk for favism, indicating the additional need for a single autosomal (not X-linked) gene to create the susceptibility to favism of G6PD-deficient persons. The active hemolytic principle in fava beans is > likely DOPA-quinone. Differences in susceptibility to favism may be related to differences in the enzymatic system that converts L-DOPA to DOPA-quinone.