"We thought for sure we'd find someone who could help him," says Tracy Seckler tells PEOPLE. "You just don't want to hear: 'There's nothing we can do.' "

When Charley Seckler was 3 years old, everyone seemed to notice his big, strong calves. “People always said, ‘Charley, you’re gonna be a soccer player,’ ” his mom, Tracy Seckler, tells PEOPLE.

But when Charley’s pediatrician said he might have muscular dystrophy, Tracy began to connect the dots. The concerned mother went online and saw videos of other kids who had her son’s same big calves, and they were all using their hands to push themselves off the floor – just like her son did. She knew instantly that Charley had Duchenne muscular dystrophy (DMD).

Duchenne is a rare, progressive, degenerative disease affecting about 1 in 3,500 boys, according to the Muscular Dystrophy Association (MDA). Children with the condition are born without the protein, dystrophin, which results in muscle degeneration. Eventually, they can’t walk, feed themselves or breathe on their own. One of the symptoms is enlarged calf muscles because the muscle tissue is abnormal and may contain scar tissue, according to the MDA. Until recently, boys with DMD usually didn’t survive beyond their teen years. Life expectancy is increasing and survival into the early 30s is becoming more common.

Tracy and Charley Seckler
| Credit: Courtesy Tracy Seckler

At the time Charley was diagnosed, Tracy — who was pregnant with Charley’s sister, Maisy, and also mom to Charley’s 5-year-old brother, Sam — quit her job as a middle school teacher so she could take Charley to doctor appointments in Boston, New York and Washington, D.C.

“We thought for sure we’d find someone who could help him,” says Tracy, 47, of Alford, Massachusetts. “You just don’t want to hear: ‘There’s nothing we can do.’ ”

But all doctors could do was prescribe her son steroids. There was no treatment. There was no cure.

Tracy and her husband, radiologist Dr. Benjy Seckler, were determined to change that. Four months after Charley’s diagnosis, they created Charley’s Fund to try to save their son.

Charley Seckler
| Credit: Courtesy Tracy Seckler

They spoke to researchers, doctors and scientists and read research papers related to Duchenne. Their first fundraiser, a jewelry auction, raised $60,000. They now sell custom jewelry and ties and even temporary tattoos on their website. They also have a letter writing campaign, an annual scavenger hunt in Central Park and they receive donations from kids’ lemonade stands.

Over the years, they have directed more than $40 million towards Duchenne research. They even rallied families of kids with Duchenne and co-founded a biotech company that is developing three new drugs.

“She really got everybody riveted and to be one voice and to fight for our kids’ lives,” says Kristen Greco, 43 of Neptune, New Jersey, whose 9-year-old son, Luke, has Duchenne. “She was really a guiding force. Not just for myself, but the entire Duchenne community.”

Kristen Greco and her son, Luke
| Credit: Courtesy Kristen Greco

Tracy and her husband have given TED talks and petitioned, lobbied and testified in front of the FDA about new drugs.

“She’s quite a visionary,” says Duchenne expert Dr. Brenda Wong, Professor of Pediatrics and Neurology and Director, Comprehensive Neuromuscular Center/MDA Clinic at Cincinnati Children’s Hospital Medical Center. “They’ve come a long way. She is brilliant. She is really able to be very objective when it comes to analyzing problems and assessing the need.”

Last September, a new drug that produces the protein missing in Duchenne patients received FDA approved.

“They have really, really put the pressure on therapeutics for Duchennes,” says Dr. Louis Kunkel, Professor of Genetics and Pediatrics at Boston Children’s Hospital and Harvard Medical School, who discovered the protein that causes Duchennes in 1987. “It’s fantastic. It’s pushed the field forward.”

The FDA-approved drug is tailored to the most common form of Duchenne, and sadly, isn’t the kind Charley has. But, there are at least six drugs in human trials, Kunkel says, and more coming.

“It’s a devastating disorder,” Kunkel says. “But there is hope on the horizon.”

Charley, now 16, is far shorter than his siblings — he’s 4-foot-2 because the steroids he has taken for 13 years have stunted his growth. “He’s the size of a fourth grader,” says Tracy. “Waitresses give him a kiddie menu and a plastic cup with Mickey Mouse on it.”

The Seckler family
| Credit: Courtesy Tracy Seckler

Charley spent the summer working at a coffee shop. He has a map of the world in his room and loves to travel. He’s been everywhere from Tanzania to Paris. He loves sushi, Frank Sinatra and can’t stop staring at his new Daniel Wellington watch. A self-proclaimed foodie, he says reading restaurant reviews is his favorite activity.

Charley skied with his family until he was 8 and he had to stop. He can still walk, but they just bought him his first manual wheelchair this summer for when they’re in airports or big cities. Charley was participating in a clinical trial, but it was suspended. Tracy hopes it will restart soon.

“It’s literally heartbreaking to know that you have to keep waiting — especially when every day there is deterioration,” Tracy says. “It’s hard. But there’s no way I can give up now.”

She’s recently convinced a group of non-profits to fund a clinical trial and is currently planning a global research meeting in Paris.

“She’s always busy,” Charley says. “I’m proud of her. She’s always working.”

Because she wants to keep him alive.

“I want to push as hard as I can,” she says. “When we first started, I thought to myself, ‘If there could have been a treatment, there woulda been a treatment.’ But that’s not always true. Sometimes you need to ask questions until there are no more questions to ask.”