House of Wonder by Rinne Groff

A crippled scientist returns to the small town where he grew up in order to investigate a strange situation which is gaining some notoriety. A young man there was shot in the head seven years ago. By all accounts he should have died, but instead he seems to have developed the miraculous ability to heal other people. Amidst the scientist's search for answers, the boy's whole family, including the boy himself, question their feelings about faith and challenge their beliefs in the existence of miracles.