I know of a similar case where kid had facial abnormalities, equilibrium issues, petit mal seizures, was in special ed.

Never contracted viruses or infections until puberty.

Then small short colds and everything else except some physical attributes disappeared. Moved to main stream school as a straight A student.

Mutants, hybrids, millenials?

Who knows, but it's curious.

There's some woman in California? who claims to have a mutant gene that makes her immune to every infectious disease on the planet. She also claims government abduction, experimentation, and attempted termination. Sounded crazy at the time... but now?