FLORENCE, Ala. (AP) — If you ask any of 6-year-old Walker Myrick's friends at Rogers Elementary School, they'll tell you he has an identical twin brother.
But, like Walker, they've never seen him.
It's because Walker, along with his twin Willis, suffered from Twin to Twin Transfusion Syndrome or TTTS.
"One will get more weight and the other will get hardly any," explained Walker's mother Brooke. "It can come on fast. Sometimes the doctors catch it. Sometimes it'll come on fast like it did with us, and within a week you can lose one or both."
It was Walker's idea to host a Walker and Willis Birthday Walk recently to honor his brother and raise funds and awareness for TTTS.
According to the TTTS Foundation's website, tttsfoundation.org, TTTS is a disease that affects identical twins in the placenta.
The disease occurs when the shared placenta irregularly distributes nutrition and blood to the identical twins. The twin who receives the extra is called the recipient and the twin receiving less is called the donor.
Brooke said because the recipient is getting a larger share, it doesn't mean it is the guaranteed survivor either.
"We can only guess (that Walker was the recipient)," Brooke said. "My specialist thought he was probably the recipient. I talked to doctors just like a year ago because I had so many questions, and they said he could have been a donor because he had growth problems."
She said Walker was 2 pounds, 15 ounces at birth.
According to the website, the recipient twin may suffer from heart failure because of excess blood and the donor may suffer from a lack of blood and nutrients. Most identical twins will share a placenta, and of those almost 15 percent will develop TTTS, and the site estimates there are at least 4,500 cases in the U.S. every year.
One of the factors in saving both twins if they suffer from TTTS is early detection, Brooke said.
That's one of the reasons the family has been promoting the walk — to raise awareness so future mothers of twins know to ask their doctors about it.
There is a laser surgery that can be performed if TTTS is caught early enough, Brooke said, but her doctor never even mentioned the possibility of the disease. By the time a specialist told her about the surgery, it was too late.
"We went four weeks between ultrasounds," Brooke said. "He didn't catch what was going on because he wasn't watching us closely enough. ... I was 22 years old, and I didn't know anything about it. My doctor didn't tell me anything about it."
Brooke's husband Michael said he didn't know anything about it either until Brooke started researching the disease online. He was 20 when she got pregnant. They were young and the doctors were telling them everything was fine, he said.
When they went back one week later, there was only one heartbeat.
"Nothing brought it to our attention, and we didn't know what was going on," he said.
Brooke said she lost Willis at 22 weeks, so she had to carry him for eight more weeks.
"It's just hard to think you're carrying around your child who's not living anymore," she said.
"Then people think that it's something you're not ever supposed to talk about."
Brooke and Michael, however, have been open about what happen with their son and other children.
Walker visits his twin brother's grave often, and Brooke and Michael's a 5-year-old daughter Jolie is quick to tell people she has four siblings, including her 18-month-old brother Cooper.
"They're both that way about him, and it's because we always acknowledge him," Brooke said.
Michael said Walker still does get upset about his brother from time to time.
Talking about it and visiting his grave, Brooke said, helps him deal with it.
"He'll talk about it still and how he misses him," Michael said. "He tries to talk with his friends about it at school. Just like bringing up the walk. He's doing pretty good about not trying to forget about it."
It was Walker's idea to have the walk.
The family attended a TTTS memorial walk in Ohio this past summer. A month later, the walk inspired Walker to ask his mother about hosting a walk closer to home.
"I kind of brushed it off, saying we're so busy, maybe when you're older," Brooke said. "He asked if that could just be his birthday party. I just couldn't tell him no. I'll make it happen somehow. But I couldn't tell him no."
Brooke learned about the Ohio TTTS walk through a support group, she said, and support groups have been instrumental for Brooke in dealing with the loss of her son.
"When it happened to me, a lot of people made me think that I couldn't talk about," she said.
That's something she never wants another young woman to have to deal with.
She said if a woman loses a twin or both her children, Brooke will contact them through an online support group.
"I refuse to not talk about it because I got told to focus on the one you have," she said. "People make you think like you're not supposed to talk about it. That's not healthy. You should be able to talk about it with your kids."
Information from: TimesDaily, http://www.timesdaily.com/