Figure 7. The role of ALDH7A1 as an alpha-aminoadipic semialdehyde (AASA) dehydrogenase.
AASA is in equilibrium with its cyclic Schiff base, piperideine-6-carboxylate (P6C). Pyridoxal phosphate (PLP) is the active form of vitamin B6 and an important cofactor in many types of reactions. Mutations in ALDH7A1 result in the accumulation of P6C and Knoevenagel adduct products between P6C and PLP, leading to the inactivation and depletion of PLP and pyridoxine-dependent seizures.