This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Misc., Subject name: Physiology
RBC transketolase deficiency is seen in 
Select and explain. 
A. Thiamine deficiency, B. Folic acid deficiency, C. Anaemia, D. Vitamin B12 deficiency
A: Thiamine deficiency
Answer: A: Thiamine deficiency 
Explanation: (A) Thiamine deficiency# TRANSKETOLASE is an enzyme of both the pentose phosphate pathway.> Transketolase activity is decreased in deficiency of thiamine, which in general is due to malnutrition. Two diseases are associated with thiamine deficiency: beriberi and Wernicke-Korsakoff syndrome.> Red blood cell transketolase activity is used in the diagnosis of Wernicke's encephalopathy and other B1-deficiency syndromes if the diagnosis is in doubt.