Triose phosphate isomerase (TPI) deficiency is a rare autosomal recessive disorder causing hemolytic anemia and severe neuromuscular dysfunction. Which metabolite accumulates in erythrocytes due to this enzyme defect?
- A Glucose-6-phosphate
- B Fructose-1,6-bisphosphate
- C Dihydroxyacetone phosphate (DHAP) ✓
- D 2,3-Bisphosphoglycerate
Correct answer: C. Dihydroxyacetone phosphate (DHAP)
Explanation
TPI catalyzes the interconversion of dihydroxyacetone phosphate and glyceraldehyde-3-phosphate. Deficiency causes DHAP accumulation, which is toxic to cells and leads to hemolytic anemia and neurodegeneration. Glucose-6-phosphate is upstream of the defect. Fructose-1,6-bisphosphate is produced by aldolase upstream. 2,3-BPG is produced by the Rapoport-Luebering shunt.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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