What is G6PD Deficiency (English)

• What is G6PD Deficiency (and its severe case called Favism)

  G6PD Deficiency is a hereditary abnormality in the activity of an erythrocyte (red blood cell) enzyme. This enzyme, glucose-6-phosphate dehydrogenase (G-6-PD), is essential for assuring a normal life span for red blood cells, and for oxidizing processes. This enzyme deficiency may provoke the sudden destruction of red blood cells and lead to hemolytic anemia with jaundice following the intake of fava beans, certain legumes and various drugs (see a complete list of drugs and foodstuffs to avoid).

  The defect is sex-linked, transmitted from mother (usually a healthy carrier) to son (or daughter, who would be a healthy carrier too; see a diagram of inheritance probabilities). This is due to the fact that the structure of G-6-PD is carried on the X chromosome: As stated by Ernest Beutler, M.D., "in females, only one of the two X chromosomes in each cell is active; consequently, female heterozygotes for G-6-PD deficiency have two populations of red cells; deficient cells and normal cells."

  The deficit is most prevalent in Africa (affecting up to 20% of the population), but is common also around the Mediterranean (4% - 30%) and southeast Asia. Please note that there are more than 400 genetic variants of the deficiency. You can determine whether you are G-6-PD deficient by a simple blood test. To determine your variant, you must test yourself at specialized genetic labs.

• The symptoms

  • Sudden rise of body temperature and yellow coloring of skin and mucous membrane.
  • Dark yellow-orange urine.
  • Pallor, fatigue, general deterioration of physical conditions.
  • Heavy, fast breathing.
  • Weak, rapid pulse.

• What to do in case of hemolytic crisis

  1. Upon detecting the symptoms listed above, you should either call your physician or pediatrician, or go directly to the nearest hospital. Avoid the intake of any drugs.
  2. You would most probably be requested to list all foodstuffs and drugs taken in the preceding 48 hours, so try to recall and list them.

• Risks

  With G-6-PD deficiency you can have a perfectly normal life, provided you avoid the drugs and foodstuffs included in our To Avoid list. It is therefore of great importance to learn whether you or your baby suffer from the deficiency, so that you can watch your diet and drug intake, and warn your physician or pediatrician.

• Can it be cured?

  The best therapy is simply to avoid the prohibited drugs and foodstuffs. In case of a hemolytic crisis, the most effective therapy is blood transfusion. In milder cases of the deficiency, transfusion is usually not required. But in others, where the rate of hemolysis is very rapid (as in all persons suffering from Favism), "transfusions of whole blood or packed cells may be useful" (Ernest Beutler, MD). In areas where G-6-PD deficiency is common, care must be taken to avoid giving G-6-PD deficient blood to the patient.

• Tips for parents

  Any boy suffering from Favism should be informed of his deficiency so he can help himself avoid the intake of the forbidden foodstuff in various situations where he is not under your supervision (such as school). You should also inform school supervisors and, where applicable, also the school caterers who provide school lunch. Best is to carry with you the To Avoid list and show it to all those who may treat your boy.