Transcript for John Cena Grants Wish to 10-Year-Old Boy

19th. Christmas and just a couple weeks away. What better way to celebrate than giving the gift of joy to a child in need. The Macy's believe campaign helps grant wishes for children with life threatening medical kbs write a letter to Santa, and they will donate up to a million dollars to make-a-wish. And a letter submitted online can make a child's wish come true. Like this one for a 10-year-old boy named Alfredo. For his entire 10 years of life, Alfredo has been a fighter. Born with a congenital heart defect, the San Antonio fourth grader struggles for air. He gets tired more easily. And sometimes his heart rate goes to 200. Reporter: The condition requires him to frequently use oxygen, sometimes a wheelchair. But it's never stopped him from embracing the fighter within. And it's that fighting spirit that drew him to wrestling and his hero, WWE super star, John Cena. John Cena! I like that if he's champion he doesn't go bragging about it. Reporter: Alfredo says he learned to master all sorts of John's move and last month got to study the moves up close when make-a-wish surprised him and his family by fulfilling his wish to meet John. It's been my lifelong dream. Now I'm going to meet him, I feel really excited. Reporter: Hello, Alfredo. Pleasure to meet you. Reporter: The fun didn't end with the meeting, there were gifts. Right now the champ is officially here. You wear it very well. Looks great on you. Reporter: Then a backstage tour and ringside seats to watch John in action. For John, Alfredo is an inspiration. It is such a gratifying feeling to be able to see the joy in the kids and the families faces. Reporter: For Alfredo, the meeting was the ultimate dream come true. I can look back and say today is the day I met John Cena. I shouldn't be feeling bad. Don't be stressed out. And just relax. Love that smile and that fighting spirit. You can help grant a wonderful wish like that one for Al grhim. Drop a letter at Macy's or submit online. Go to "Good morning America" on Yahoo to find out more.

This transcript has been automatically generated and may not be 100% accurate.