What toxin is responsible for toxicity associated with mushrooms mistaken for true morels (Morchella spp.)?
Gyromitrin found in false morels (Gyromitra esculenta). Gyromitrin is metabolized to monomethylhydrazine which inhibits pyridoxal phosphokinase, thereby preventing the activation of pyridoxine to pyridoxal 5-phosphate, a required cofactor for glutamic acid decarboxylase conversion of glutamate to GABA. In addition to seizures, patients may also have late-onset GI toxicity, hepatic injury, and acute kidney injury.
KH Horowitz, et al. Gyromitra Musrhoom Toxicity. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan. Updated 4 May 2021. https://www.ncbi.nlm.nih.gov/books/NBK470580/