Teen organ recipients who met as babies to attend homecoming dance together

"It's heartwarming," said Oula Haddad, mother to 16-year-old Grace Haddad.

— -- Two teenagers who met as they battled the same metabolic disorder and then underwent liver transplants weeks apart, are now going to a homecoming dance together.

"It's heartwarming," said Oula Haddad, mother to 16-year-old Grace Haddad of Olney, Maryland. "To think your child is doing something so normal as going to a homecoming dance, I think it's something a lot of people take for granted."

Jakob “JJ” Jasin, 17, and Grace Haddad's families first met in 2001 when they were being treated at the same hospital for maple syrup urine disease (MSUD) -- a recessive metabolic disorder where the body is unable to process protein normally.

In 2004, JJ and Grace both received liver transplants just three weeks apart to treat their conditions.

In some cases, if left untreated, MSUD could cause severe brain damage, according to Dr. George Mazariegos, chief of pediatric transplantation at Children’s Hospital of Pittsburgh of UPMC.

Mazariegos performed the transplants on both JJ and Grace 13 years ago. Mazariegos said the surgery restored enough of the enzyme his patients needed to allow normalization for their diets, while freeing them from possible neurological disorders.

"In a nutshell, the liver transplant really allows the life to be returned back to a normal one," Mazariegos told ABC News. "It's been great to see them now after 13 years to see how they're growing and just enjoying life."

JJ's mom, Susan Jasin of Ashburn, Virginia, said she and the Haddad family first met at Walter Reed National Military Medical Center in Bethesda, Maryland, when the kids were just a few days old.

Since then, JJ and Grace have maintained a lifelong friendship. The pair have attended Camp Chihopi Liver & Intestine Transplant Summer Camp together over the years.

"They went to camp this year and deepened their relationship as friends," Susan Jasin told ABC News. "I think them having a common bond, they're able to rely on each other as a source of support."

On Sept. 23, JJ and Grace will attend the homecoming dance at Rock Ridge High School in Ashburn, Virginia, where JJ is a senior.

"Every time I would tell the story that he was taking her to homecoming, it would just make me smile," Jasin said. "It would make my heart happy. It also puts the awareness out there for how critical the need is for people to have an organ donation and how life goes on through organ donation."