A disorder characterized by an extreme sensitivity to the broad bean VICIA FABA (fava). If an affected person eats these beans, a chemical in the bean causes rapid destruction of red blood cells, leading to a severe type of anaemia (see anaemia, haemolytic).
Favism is uncommon except in some areas of the Mediterranean. The disorder is caused by a sex-linked genetic disorder. Affected people have G6PD deficiency, a defect in a chemical pathway in their red cells that normally helps protect the cells from injury.
Children with a family history of favism can be screened for the disorder at an early age. If it is found, they must avoid fava beans and certain drugs, including some antimalarial drugs and antibiotic drugs, that can have a similar effect on their red blood cells.
A type of haemolytic ANAEMIA, attacks of which occur within an hour or two of eating broad beans (Vicia fava). It is a hereditary disease due to lack of an essential ENZYME called glucose-6phosphate dehydrogenase, which is necessary for the continued integrity of the red cell. This defect is inherited as a sex-linked dominant trait, and the red cells of patients with this abnormality have a normal life-span until challenged by certain drugs or fava beans when the older cells are rapidly destroyed, resulting in haemolytic anaemia. Fourteen per cent of African-Americans are affected and 60 per cent of Yemenite Jews in Israel. The perpetuation of the gene is due to the greater resistance against MALARIA that it carries. Severe and even fatal HAEMOLYSIS has followed the administration of the antimalarial compounds pamaquine and primaquine in sensitive individuals. These red cells are sensitive not only to fava beans and primaquine but also to sulphonamides, acetanilide, phenacetin, para-aminosalicyclic acid, nitrofurantoin, probenecid and vitamin K analogues.
n. an inherited defect in the enzyme glucose-6-phosphate dehydrogenase causing the red blood cells to become sensitive to a chemical in fava beans (broad beans). Eating these beans results in destruction of red blood cells (haemolysis), which may lead to severe anaemia, requiring blood transfusion. Favism occurs most commonly in the Mediterranean and Middle East. See also glucose-6-phosphate dehydrogenase deficiency.
An ENZYME that performs an essential function in the metabolism of CARBOHYDRATE. A de?ciency in this enzyme – acronym G6PD – results in the breakdown of ERYTHROCYTES (HAEMOLYSIS), usually in the presence of oxidants (see OXIDANT) such as infections or drugs. The de?ciency disorder is a hereditary condition in which the enzyme is absent. The condition, characterised by pallor, rigors and pain in the loin, is divided into African, European (including FAVISM) and Oriental types. Sufferers should avoid substances that trigger haemolysis. Acute episodes are best treated symptomatically.... glucose-6-phosphate dehydrogenase
A generally unexpected, so unpredictable, abnormal reaction to a drug caused by a constitutional defect in the patient. In some cases the underlying disorder is already known or discovered after the ?rst event, so that the drug in question can be avoided thereafter. The abnormal sensitivity of patients with PORPHYRIAS to BARBITURATES is an example. Hereditary biochemical defects of red blood cells are responsible for many drug-induced haemolytic anaemias (see under ANAEMIA) and for FAVISM. Porphyria variegata, the South African variety of porphyria, is an example of an inborn error of metabolism which was without serious symptoms until the advent of barbiturate drugs, prescription of which is now strongly discouraged. If anyone with this metabolic disorder takes barbiturates, the consequences may be fatal.... idiosyncrasy
a hereditary disorder – an X-linked condition (see sex-linked) – in which the absence of the enzyme glucose-6-phosphate dehydrogenase (G6PD), which functions in carbohydrate metabolism, results in the breakdown of the red blood cells (*haemolysis), usually after exposure to *oxidants, such as drugs, or infections. The breakdown causes acute attacks that are characterized by pallor, loin pain, and rigors. There are several varieties of G6PD deficiency, which is most common in people of African, Middle Eastern, and Mediterranean descent. Treatment involves identifying and avoiding agents that trigger the haemolysis and treating acute attacks symptomatically. See also favism.... glucose-6-phosphate dehydrogenase deficiency
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