Download What is G6PD Deficiency

King AbdulAziz University
Clinical Nutrition Department
Genetics
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.
The defect is sex-linked, transmitted from mother (usually a healthy
carrier) to son (or daughter, who would be a healthy carrier too. This is
due to the fact that the structure of G-6-PD is carried on the X
chromosome.
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.
Risks
With G-6-PD deficiency you can have a perfectly normal life, provided
you avoid the drugs and foodstuffs in the diet below.
The G6PD diet:
The G6PD diet is very easy to follow. However, if you don’t follow your
diet you can get very sick. Some people become so ill that they have to be
admitted to the hospital.
All fava Beans and food that are made with them like: Foule modems&
Falafel should be avoided. Because A substance in fava beans called
isouramil (IU) triggers the hemolytic anemia in G6PD-deficient
individuals, and it is this interaction of IU with G6PD erythrocytes which
renders these red blood cells incapable of supporting the growth of the
malarial pathogen (Plasmodium falciparum).
Drugs and chemicals that should be avoided by persons with
G6PD Deficiency:
Analgesics / Antipyretics
Acetanilid, acetophenetidin (phenacetin), amidopyrine (aminopyrine),
antipyrine, aspirin, phenacetin, probenicid, pyramidone.
Miscellaneous:
Alpha-methyldopa, ascorbic acid, dimercaprol (BAL), hydralazine,
mestranol, methylene blue, nalidixic acid, naphthalene, niridazole,
phenylhydrazine, toluidine blue, trinitrotoluene, urate oxidase, vitamin K
(water soluble), pyridium, quinine.
Antimalarials:
Chloroquine, hydroxychloroquine, mepacrine (quinacrine), pamaquine,
pentaquine, primaquine, quinine, quinocide.
Cytotoxic / Antibacterial:
Chloramphenicol, co-trimoxazole, furazolidone, furmethonol, nalidixic
acid, neoarsphenamine, nitrofurantion, nitrofurazone, para-aminosalicylic
acid.
Cardiovascular Drugs:
Procainamide, quinidine.
Sulfonamides/ sulfones:
Dapsone, sulfacetamide, sulfamethoxypyrimidine, sulphanilamide,
sulfapyridine, sulfasalazine, sulfisoxazole.
Diagnosing and Treating G6PD Deficiency:
In most cases, cases of G6PD deficiency go undiagnosed until a child
develops symptoms. If doctors suspect G6PD deficiency, blood tests
usually are done to confirm the diagnosis and to rule out other possible
causes of the anemia.
If you feel that your child may be at risk because of either a family
history or your ethnic background, talk to your doctor about performing a
screening with blood tests to check for G6PD deficiency.
Treating the symptoms associated with G6PD deficiency is usually as
simple as removing the trigger — that is, treating the illness or infection
or stopping the use of a certain drug. However, a child with severe
anemia may require treatment in the hospital to receive oxygen, fluids,
and, if needed, a transfusion of healthy blood cells. In rare cases, the
deficiency can lead to other more serious health problems.