Although he’s only a little over a year old, Nolan Morel is a bona fide charmer. Clad in a red shirt and navy blue suspenders, he flashes a happy grin at his mother, Rosalia; his physician, Dr. Laura Lehman; and the others in the room. “Look at those dimples!” someone coos, and he giggles in response. “I can’t believe how social he’s being,” laughs Rosalia. “He wasn’t always like this.”

In fact, Nolan’s first several days of life were anything but lighthearted. Just a few hours after his birth at a hospital north of Boston, he stopped breathing and had to be manually resuscitated and given oxygen. When these frightening episodes continued on and off for the next day, his physicians contacted the Critical Care Transport team from Boston Children’s Hospital. …