I can say this: my mother has struggled for many, many years trying to figure out what's wrong with her and causing her weird, debilitating symptoms. She finally, at long last got a diagnosis that her doctors are pretty confident in: advanced Sjögren's.

Out of curiosity, I punched her symptoms into ChatGPT, and - without access to any test results - Sjögrens was its #2 guess, and it suggested diagnostic tests that she had done and had shown it was Sjögrens. Sjögrens actually isn't super-rare (about a percent or so of the population has it), but usually much milder, and very underdiagnosed.

I think AI tools are seriously underappreciated with respect to proposing new lines of investigation on hard-to-crack cases.