Sad ending to a hopeful story. Can't think of many rare fatal genetic reactions to anesthesia specifically besides MH. Having never seen it myself, I fear I have developed a simulation-induced misconception that you just need to recognize it and push the dantrolene and everything will be fine. Clearly not always the case.
"Recently, two reports describing children carrying several polymorphisms and mutations in the MTHFR gene were published. The children developed catastrophic neurologic outcomes after being anesthetized with nitrous oxide."