JEFFERSONVILE, Ind. (WDRB) -- Sheer joy turned to heartbreak when a Jeffersonville couple learned their newborn baby had a rare and life-altering disease. Today, they hold out hope for a cure, one step at a time. 

A baby's first steps is a moment moms and dads cherish. But doctors told Daniel and Ashley Brown their son, Arthur, may never take them. He suffers from Prader Willi Syndrome, a rare genetic disorder impairing his 15th chromosome. 

"It makes you fight a little harder to say, 'I'll prove you wrong,'" said Ashley Brown. 

"It's a whole functionality of the metabolic system and the nervous system," said Ashley Brown. "Not everything is sending the right signals from that part of the brain to the next part of the brain."

When we first met this family in April of 2015, baby Arthur lived like a science experiment.

"We had close to 20 different specialties going at one point," said Ashley Brown.

He's endured 500 doctor visits in less than two years, with 25 hospital stays. He struggled to suck, swallow, and breathe, and ate from a tube -- and doctors warned that, as an adult, Arthur may never feel full. Prader-Willi is most often linked to life-threatening obesity.

"What we can do is treat some of the symptoms that go along with Prader-Willi, we can treat -- of course -- the conditions that go along with that, but we can't change the actual condition itself," said Dr. Klaus Boel, a pediatrician. "The main thing with Prader-Willi is of course that people get lots of support group involvement." 

It's why the Browns dedicated their lives to fighting this disease, which affects only one in every 15,000 to 25,000 live births. In a mission called Arthur's Angels on Saturday, they'll host a benefit walk at Perrin Park in Jeffersonville. All proceeds go toward Prader Willie Research.

For more information on Arthur's Angels, CLICK HERE.

The walk at Perrin Park starts at 10:30 Saturday morning. It's Arthur's second birthday and he will participate with the help of a walker. 

"You know his legs are small, but he is mighty and he will go as far as he can go," said Ashley Brown.

It's one small step toward a cure -- and a giant leap for a family with hope. 

"I believe down in my heart that he will be cured before our lifetime is over," said Daniel Brown.

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