Based on what you know about this case, which of the three catalytic subunits of the $\alpha$-ketoglutarate dehydrogenase complex would you expect to demonstrate decreased activity in this subject?
E1 ($\alpha$-ketoglutarate dehydrogenase), which requires TPP
E2 (dihydrolipoyl succinyltransferase), which requires lipoic acid and CoA
E3 (dihydrolipoyl dehydrogenase), which requires FAD and NAD$^+$
All these subunits will be equally impaired.
No subunit will be impaired.