Tori McClosky’s senior year of high school turned upside down when a tumor was found on her brain. The cause was neurofibromatosis type 1 (NF1), a genetic condition that causes tumors to grow on nerves in the brain and throughout the body.

“I went from planning prom and playing soccer to shaving my hair off and preparing for brain surgery,” she recalls. “It was shocking. I was living my life, and everything was great until I got...