Most common enzyme deficiency causing hemolytic anemia?
High-Yield Explanation
Ans. c (Glucose-6-phosphate dehydrogenase) (Ref. H - 18th/ch. 106; Harper 27th/pg. 127)Genetic deficiency of glucose 6-phosphate dehydrogenase, the first enzyme of the pentose phosphate pathway, is a major cause of hemolysis of red blood cells, resulting in hemolytic anemia and affecting approx 100 million people worldwide.GLUCOSE-6-PHOSPHATE DEHYDROGENASE (G6PD) DEFICIENCY# It is the most common human enzyme deficiency.0# It is the most common enzyme deficiency causing hemolytic anemia.0# Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked recessive disease featuring nonimmune hemolytic anemia in response to a number of causes.0# The classic reaction to consumption of broad beans has led to the commonly used term favism.# It confers protection against malaria, in particular the form of malaria caused by Plasmodium falciparum.Q# Drugs that can cause hemolysis in G6PD deficiency:- Primaquine (an antimalarial)- Sulphonamide antibiotics- Sulphones (e.g., dapsone, used against leprosy)- Other sulphur-containing drugs: glibenclamide (an antidiabetic drug)- Nitrofurantoin (an antibiotic often used for urinary tract infections)- Vitamin K analogues# Lab features of GPD deficiency:- In active G6PD, "Heinz bodies" (aggregates of protein) can be seen in RBCs on a blood film;0- Haptoglobin is decreased in hemolysis;- A "direct antiglobulin/Coomb's" test-negative, as hemolysis in G6PD not immune-mediated;- When there are sufficient grounds to suspect G6PD, a direct test for G6PD is the "Beutler fluorescent spot test", which has largely replaced an older test (the Motulsky dye-decolouration test).- The Beutler fluorescent spot test is a rapid and inexpensive test that visually identifies NADPH produced by G6PD under ultraviolet light.