Cause of Port-Wine-Stain Birthmarks Pinpointed
Single, random change to gene during fetal development causes birthmarks and the more serious Sturge-Weber syndrome
"For some parents, it's going to be a huge relief," Ball said. "It's a huge lodestone that people carry for a while."
Ball said she didn't really feel the weight of her own guilt lift until recently, when she heard the news of the discovery.
"I didn't know if I had caused it," she said. "But I always felt that if I had caused it, then it was my responsibility to make it right."