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.

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An acute condition seen chiefly in Italy, following the ingestion of certain species of beans, e.g., Vicia faba, or inhalation of the pollen of its flower; characterized by fever, headache, abdominal pain, severe anemia, prostration, and coma; it occurs in certain individuals with genetic erythrocytic deficiency of glucose 6-phosphate dehydrogenase. Chance exposure to the Vicia faba, by its impact on the phenotype of glucose-6-phosphate dehydrogenase, impinges on the expression or the gene, an example of incomplete penetrance. SYN: fabism. [Ital. favismo, from fava, bean]

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fa·vism 'fä-.viz-əm, 'fā- n a condition esp. of males of Mediterranean descent that is marked by the development of hemolytic anemia upon consumption of broad beans or inhalation of broad bean pollen and is caused by a usu. inherited deficiency of glucose-6-phosphate

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n.

an inherited defect in the enzyme glucose-6-phosphate dehydrogenase causing the red blood cells to become sensitive to a chemical in broad beans. It results in destruction of red blood cells (haemolysis), which may lead to severe anaemia, requiring blood transfusion. Favism occurs in parts of the Mediterranean and Iran. See also glucose-6-phosphate dehydrogenase deficiency.

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fa·vism (faґvis-əm) [Italian fava bean] an acute hemolytic anemia caused by ingestion of fava beans or inhalation of the pollen of the plant Vicia faba (fava), occurring in susceptible individuals usually as a result of a hereditary deficiency of glucose-6-phosphate dehydrogenase in erythrocytes; see glucose-6-phosphate dehydrogenase deficiency.