MADISON, AL - There's never a dull moment at the Revera home in Madison. Parents Cindy and Greg have four boys who don't stop moving. However, two of these brothers now have an unbreakable bond because of events that have unfolded in the last year.

In March, Cindy and Greg noticed their oldest son, A.J., was bruising easily and acting tired. A.J. hit his head, and Cindy said the bruise on her son's head from that injury was bigger than it should have been. They took him to his pediatrician, Dr. Robbie Dudley, who tested his blood and noticed A.J. had a very low platelet count. He also had strep. Medicine cleared up the strep, but the platelets remained low.

After about a month of tests, doctors found the root of what was causing A.J.'s blood cells to be low. They diagnosed him with aplastic anemia at the end of April. Aplastic anemia is a condition where the bone marrow doesn't make blood cells like it should. Once he was diagnosed, A.J. got platelet transfusions every seven to 10 days to help him stay healthy while parents Greg and Cindy worked with doctors to determine the best course of action.

"Once we had a diagnosis, we knew what we were looking at, and moving forward, it was devastating, but you also knew what path we were on, and we could move forward, whereas we spent about eight weeks of not knowing, and back and forth, then, 'could it be this,' and 'could it be that,' and your mind always wanders to the worst."

Cindy and Greg learned A.J. would need a bone marrow transplant. For people who need these, the best option is a sibling match. A.J. was lucky, because the family learned in May that younger brother Austin was that match.

"It made me feel happy, because it meant I wouldn't have to wait, and we could get it over, done, fast," A.J. told us.

In July 2009, A.J. and Austin went through the procedure at Vanderbilt Children's Hospital in Nashville. The first step was to get rid of A.J.'s bad bone marrow. So, he underwent four days of intense chemotherapy to kill it off. During that time, A.J. lost his hair.

"When he lost his hair, I had a deal with him," said A.J.'s father, Greg. "When he lost his hair, he'd go ahead the cut mine off, so he actually shaved my hair off at the hospital and had a pretty good time doing it."

"The other boys did it too, and actually, it was taking such a negative thing that was part of it, and it became such a positive thing that was such a happy day," said mom Cindy. "They had so much fun, and actually looking back at our hospital days, it was one of our most fun days, just because Greg did a good job turning it in to 'hey, let's make this fun'."

The next step was the transplant. Doctors took some of Austin's good bone marrow from his hip. You might be wondering if this was painful for a young child.

"They said my bone would hurt for a few days," Austin said in the hospital. "Does it hurt right now?" asked Dad, Greg. "Um, only a little bit." "Are you okay, that it hurts just a little bit?" Dad asked him. "Yeah, I'm fine," said Austin, who is now in kindergarten at Horizon Elementary.

With bone marrow transplants, sibling matches are the best type. However, not everyone has a brother or sister, and if they do, their bone marrow may not match. According to Be The Match, the National Marrow Donor Program, 70% of people who need marrow transplants do not have a matching donor in their family.

"For some, it's about one in 20,000. The possibility for others, based on their nationality, their race, background, it can be as much as one in a million, and, so, looking at that, we realized how lucky we were," said Cindy Revera.

Now, to AJ's special Christmas wish. He knows there are thousands of patients who desperately need help right now. A.J. wants to get 100 people to sign up for the National Bone Marrow Registry by the end of the year.

"I'm helping other children that need help," A.J. told us.

A.J. asks people to sign up through his blog. On his blog, you'll see a special link where your registration will count under A.J.'s name. Here's the direct link.

Once you go to the link, follow the directions. The registration process takes about 15 to 20 minutes. Be The Match will then send you a packet to complete, and swabs for your cheeks. You then mail the packet back and your swabs will be processed.

"In looking at it, knowing what [A.J.] went through, it's such a small thing for then saving a life," said Cindy Revera. "Now, sitting where I am, I would do it for anyone that I could in a heartbeat."

Note: A.J. has already met his goal of 100 people, but he would love to exceed that goal! Please consider joining the registry.

A.J. also writes about his health progress on his blog. Six months after his transplant, his platelets are up and his weekly checkups at Vanderbilt have been extremely positive. Cindy, a former elementary school teacher, is home-schooling A.J. this year, but A.J. keeps up with his classmates and teacher at Horizon through email and Skype.

"They have supported me in sending me cards, and when I was in the hospital, they came to visit me, and because they couldn't be around people, they waved from the parking lot," said A.J.

Greg and Cindy Revera say it's easy for them to support their son's Christmas wish.

"We've had a very rough year, and to end it on something positive, and to be taking his wish, and trying to get that fulfilled is the greatest gift I could give back to him," said Cindy.

"We've been very blessed, very lucky," said Greg. "It's been such a trying year, and we've been through the lowest lows and the highest highs, and this is a good way to end it."

To join the Be The Match Registry, you must be between 18 and 60 years of age, be in overall good health and understand the commitment of the donation process.