The first hint that something wasn’t quite right with Danny Sanchez-Garcia’s heart came at his mom’s six-month prenatal visit.

“There was a little blip on the ultrasound, but then it was gone on the next one, so they didn’t think it was anything and I didn’t worry any more about it,” says Danny’s mom, Cynthia.

Cynthia was overjoyed when Danny was born at her local hospital seeming perfectly healthy. But as the hospital staff monitored Danny overnight, they noticed his oxygen level was lower than normal and decided to run more tests. His doctors believed the tests pointed to a congenital heart defect called tetralogy of Fallot with pulmonary atresia.

“They transported him overnight to Boston Children’s Hospital,” says Cynthia. “I felt like I was on a roller coaster, especially as a first-time mom.” …