Glucose-6-phosphate dehydrogenase deficiency is a hereditary enzyme defect that causes red blood cells to prematurely rupture when exposed to oxidative stresses. It is an X-linked condition affecting 10-15% of American black males. Those with the deficiency usually have no issues until exposed to triggers like fava beans, certain drugs, or infections, which cause hemolytic anemia symptoms like jaundice and dark urine. Laboratory tests during a hemolytic episode will show signs of ruptured red blood cells like increased bilirubin, hemoglobin in blood and urine, low haptoglobin, and Heinz bodies visible on blood smears. Treatment focuses on avoiding triggers through medication warnings and blood transfusions for severe anemia.

1. Glucose 6-phosphate
dehydrogenase deficiency
anemia
DR. AHMAD KHAN

2. definiation
 hereditary enzyme defect that causes episodic hemolytic anemia
because of the decreased ability of red blood cells to deal with oxidative
stresses
 Excess oxidized glutathione that forces hemoglobin to denature
and form precipitants called Heinz bodies
 Heinz bodies cause red blood cell membrane damage, which leads to
premature removal of these red blood cells by reticuloendothelial cells
within the spleen (i.e, extravascular hemolysis)

3.  Numerous G6PD isoenzymes
 usual isoenzyme found in American Blacks is designated G6PD-A and that
found in Whites is designated G6PD-B
 both of which have normal function and stability and therefore no
hemolytic anemia
 10 to 15 % of American Blacks have the variant G6PD isoenzyme
designated A–, in which there is both a reduction in normal enzyme
activity and a reduction in its stability

4.  The A– isoenzyme activity declines rapidly as the red blood cell ages past
40 days, a fact that explains the clinical findings in this disorder
 More than 150 G6PD isoenzyme variants have been described, with very
low enzyme activity, episodic hemolysis, and exacerbations due to
oxidizing substances including fava beans
 protected from malaria parasitic infection, have less coronary artery
disease, and possibly have fewer cancers and greater longevity

5. Sign and symptoms
 X-linked disorder affecting 10–15% of American hemizygous Black males
and rare female homozygotes
 usually healthy, without chronic hemolytic anemia or splenomegaly
 Acute Hemolysis trigger with:
1. Fava bean
2. Drugs
3. Infections

6.  hemolytic attack starts with malaise, weakness, and
abdominal or lumbar pain.
 Within a timeframe of several hours to 2–3 days, the patient
develops jaundice and often dark urine
 Drugs that cause Hemolysis: dapsone, methylene blue,
phenazopyridine, primaquine, rasburicase, toluidine blue,
nitrofurantoin, trimethoprim/ sulfamethoxazole, sulfadiazine,
pegloticase, and quinolones

7.  hloroquine, quinine, high-dose aspirin, and isoniazid, have
been implicated but are less certain as offenders
 Severe G6PD deficiency (as in Mediterranean variants) may
produce a chronic hemolytic anemia
 anemia is moderate to extremely severe, usually normocytic
and normochromic, and due partly to intravascular hemolysis

8. Laboratory exam
 Between hemolytic episodes, the blood is normal.
 During episodes of hemolysis, the hemoglobin rarely falls
below 8 g/dL (80 g/L
 there is reticulocytosis
 increased serum indirect bilirubin

9.  Hemoglobinemia
 Hemoglobinuria
 high LDH
 low or absent plasma haptoglobin

10.  peripheral blood cell smear often reveals a small number of “bite” cells—
cells that appear to have had a bite taken out of their periphery, or
“blister” cells
 indicates pitting of precipitated membrane hemoglobin aggregates (ie,
Heinz bodies) by the splenic macrophages
 Heinz bodies may be demonstrated by staining a peripheral blood smear
with cresyl violet;
 they are not visible on the usual Wright-Giemsa–stained blood smear

14.  Specific enzyme assays for G6PD reveal a low level but may
be falsely normal if they are performed during or shortly after
a hemolytic episode during the period of reticulocytosis.
 In these cases, the enzyme assays should be repeated weeks
after hemolysis has resolved.
 In severe cases of G6PD deficiency, enzyme levels are always
low

15. Treatment
 No treatment is necessary except to avoid known oxidant medications
 if the anemia is not severe, regular folic acid supplements and regular
hematologic surveillance will suffice.
 It will be important to avoid exposure to potentially hemolytic drugs, and
blood transfusion may be indicated when exacerbations occur, mostly in
concomitance with intercurrent infection
 If anemia is severe blood transfusion

16. Thanks
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