2. Also called FAVISM
G6PD is an enzyme of hexose monophosphate shunt .
It is needed for the synthesis of Reduced Glutathion which protects RBCs
membrane and Hb against oxidative damage .
It is X-linked recessive affected mainly males , but can occur in females .
The hemolysis is intravascular .
3. The RBCs become liable to destruction by O2 radicles .
The defect is either functional ( the enzyme is not functioning ) or quantitative
( the quantity of enzyme is not enough ) .
4. Precipitatng Factors For Hemolysis :
Usually the patient is normal and there is no hemolysis except in :
1- Ingestion of favabeans ( usually fresh ) , leads to liberation of O2
radicles leading to RBCs damage .
2- infections : It leads to increased activity of neutrophils which will try to
combat the infection by liberation of O2 radicles causing RBCs damage.
6. Clinical Features :
The patient is normal but when exposed to the any of the above
precipitating factors , there will be sudden and rapidly developing
anemia , jaundice , fever and dark urine due to hemoglobinuria .
8. 6- Enzyme assays ( definitive diagnosis ) .
In patients with active hemolysis , the enzyme assay will be normal because
there are some RBCs are enzyme deficient and other RBCs are normal , so
when hemolysis occurs the only abnormal RBCs are destroyed and the
normal will stay , so when we do the enzyme assays we will find normal
enzyme assay , so we should wait for one month at least after active
hemolysis and then do the test .
Also following blood transfusion , the test will be normal .
9. Treatment
1- Avoid precipitating factors .
2- For acute attacks :
Rest
Withdrawal of the drugs
Blood transfusion for symptomatic anemia
folic acid
