Kimberly Greenberg, of Westport, had a fairly easy pregnancy and delivery with her first child, Parker, but the challenges started almost immediately.

"It was the next day. She failed her hearing test in the hospital," Kimberly explained. "That was kind of the first, 'Oh, no.'"

Parker's hearing would improve after about four months. But the Greenbergs' journey of doctors’ appointments was just beginning. Over the years, Parker has been to all types of therapy, including physical, occupational, speech, equine and aqua.

"We went to our pediatrician who took one look at her as a follow-up and was like, ‘You know what? Her eyes look a little off. You should probably go see an eye doctor, and you probably should go see a neurologist and geneticist. There's more going on with her,'" Kimberly said.

Kimberly and her husband, Jason, took Parker to specialist after specialist but left without answers. In the meantime, Parker kept missing milestones.

"As you start to see kids her same age walking and running around, it was an emotional roller coaster for us," Kimberly told News 12.

Then a week before Parker's second birthday, she was diagnosed with a rare genetic condition.

"She has what's called HIST1H1E syndrome. It's a lot of developmental delays, intellectual disabilities," Kimberly explained. "She's had three eye surgeries that come from this. She has seizures, which we've had a couple scares with."

Doctors didn't even discover HIST1H1E syndrome until after Parker was born. She was just the eighth case in the world at the time.

"It was such a rare genetic disorder that even the specialists would look at you like, 'What is this?'" Jason recalled. "And that was the unsettling part. It was the wild, Wild West. You had no real clear path of how to take the next steps."

So, Kimberly decided to make a path.

"My wife's definitely an advocate. She's a bulldog in a good way where she seeks to find an answer," Jason told News 12.

Kimberly started a Facebook group for parents of kids with HIST1H1E. She said it's since grown to about 75 families. Then she reached out to Dr. Yong-Hui Jiang, who was at Duke University Hospital at the time.

"Parker's mom contacted me because we discovered, reported the first case in the United States," Jiang said. It turned out Jiang was moving up to the Yale School of Medicine to become the chief of medical genetics.

"It was kind of like the stars aligned," Kimberly recalled.

Jiang is now researching HIST1H1E in his lab at Yale with hopes of one day finding a cure. It’s work that’s possible because of the Greenbergs. The syndrome affects such a small percentage of people that it's hard to get federal funding to study it, so Parker's parents created the HIST1H1E Genetic Syndrome Research Foundation, a parent-led nonprofit that funds Jiang's research.

Jiang told News 12 the condition is the result of a "very subtle mistake," a single gene's spontaneous mutation, which can only be detected with a specific test. He said with HIST1H1E not identified until 2017, there's a large gap in the medical understanding of it, one he hopes to change with help from the Greenbergs.

Under the foundation, Kimberly and Jason also came up with Parker's Cure to raise money locally. So far, they've brought in $235,000.

"It's really thanks to our community we live in, our friends, our family," Kimberly said.

All of them have celebrated Parker's wins over the years, like when she walked for the first time.

"Here's this milestone, that, no, she's not a year old starting to walk or no, she's not 2 years old. She was a little over 4, and it was kind of like everyone like felt it, like felt the emotion. I think I just like went to tears," Kimberly remembered.

"And now she can be commonly found walking around our kitchen island. We call her the mall walker," Jason joked. “She loves to just stroll. She has a big smile on her face. And when she does something new for the first time, she can sense it."

Along the way, Parker's sisters Skyler and Quinn have cheered her on.

"Parker and her sisters are so close. Her little sisters, who are 4 1/2 and 3, kind of act like the big little sisters. They really do take care of her," Kimberly said. "They've asked a few questions, why Parker isn't talking the same or can't run like they can, but they really just embrace her, and they love her."

So has their town of Westport. Parker is in kindergarten at Coleytown Elementary School.

"I drop her off at school and everyone approaches Parker. Everyone knows Parker," Jason told News 12. "As a father, it's really warming to see so many people have so much invested in Parker."

Parker needs round the clock care, but the hope is Jiang's research will one day lead to a more independent life.

"She's proved us wrong with a lot of things, but I think for the most part she's probably always need some assistance, " Kimberly explained. "But she's a happy girl, and she'll live a happy amazing life with family that loves her and a whole community that's always behind her."

To learn more about HIST1H1E syndrome or donate to the cause, click here.