AASDH and developmental and epileptic encephalopathy: Pyridoxine-dependent epilepsy (PDE-ALDH7A1), also referred to as early-onset vitamin B6-dependent epilespy-4 (EPEO4, OMIM 266100) due to the deficiency of α-aminoadipic semialdehyde dehydrogenase (α-AASA, also known as antiquitin; E.C. 1.2.1.3), is a developmental and epileptic encephalopathy (DEE) characterized by seizures resistant to standard medications and responsive to pyridoxine treatment (Coughlin et al., 2022; Coughlin et al., 2021; Coughlin et al., 2019; Stockler et al., 2011).