The TLC show My 40-Year-Old Child documents a rare and mysterious ailment that stunts development in children, leaving adults looking like kids.
Pam Brink, a mom from Marco Island, Fla., has a son who's 29, but has the body of a 10-year-old and the mental development of a child even younger:
Brink said her son Jeffrey was diagnosed after she noticed he wasn't aging the way he was supposed to and was suffering from severe handicaps.
"It was hard because there's a lot of challenges with taking care of a baby, which is what Jeffrey really is," she told the Huffington Post in an interview.
"He's probably between eight and 12 months as far as needing to be taken care of."