G6PD deficiency is an X-linked genetic disorder caused by a deficiency in the enzyme glucose-6-phosphate dehydrogenase, which protects red blood cells from oxidative damage. Patients are generally asymptomatic until exposed to precipitating factors like fava beans, certain drugs, infections, or stress, which can cause acute hemolytic anemia. Diagnosis involves blood tests showing anemia, reticulocytosis, elevated bilirubin and LDH, Heinz bodies or bite cells on blood smear, and enzyme assays after recovery from hemolysis. Treatment focuses on avoiding triggers and supportive care with rest, transfusions, and antibiotics for infections.

1. G6PD Deficiency

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.

5. 3- Drugs :
** Antimalarial : primaquine , chloroquine .
** Analgesics : Aspirin , phenacetin
** Antibiotics : Sulphonamides , nitrofurantoin , ciprofloxacin
** Miiscellaneous : quinidine , vitamin K , dapsone
4- Surgery and stressful conditions .

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 .

7. Investigations :
1- Anemia .
2- Reticulocytosis .
3- Increased indirect bilirubin .
4- Increased LDH .
5- Blood film : ** Heinz bodies
** bite cells

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

10. Any infection should be treated
The condition will resolve in 10 – 14 days .