By Gabrielle Olya
Updated November 15, 2016 05:01 PM

Michelle Sie Whitten grew up not knowing anyone with Down syndrome — until she had a daughter with the disorder.

“Growing up in New Jersey, I had never met anybody with Down syndrome or even in a wheelchair. Then, when I was pregnant I got a pre-natal diagnosis,” Whitten, president of the Global Down Syndrome Foundation, tells PEOPLE. “I met a few kids with Down syndrome, and I was like, ‘Alright, we can do this!’ Then we never looked back.”

Whitten admits that because she didn’t encounter people with Down syndrome growing up, she had a negative stereotype about what they were like.

“The stereotype in my mind was a person with their tongue hanging out and a bad haircut, dressed in ill-fitting clothes,” she says. “There were terrible stereotypes in my mind, and I realized it was fabricated.”

So when she was coming up with the idea for Global’s annual fundraiser, she wanted to do something that would shatter stereotypes.

WATCH: Model with Down Syndrome Makes New York Fashion Week History!

“I wanted to take people with Down syndrome and make them models,” says Whitten. “Not only are they not the stereotype, but they’re beautiful models, and we’re going to elevate them [by having them walk the runway] with Hollywood celebrities.”

On Saturday, Global held its eighth annual Be Beautiful Be Yourself Fashion Show in Denver, and Hilary Swank, Queen Latifah, Peyton Manning and more stars walked the runway alongside models with Down syndrome.

Credit: Courtesy Global Down Syndrome Foundation
Credit: Courtesy Global Down Syndrome Foundation
Credit: Courtesy Global Down Syndrome Foundation

For the participating models, the event can be life-changing.

“We hear directly from them and we hear from their families that it is in many cases one of the best days of their life,” says Whitten. “People with Down syndrome are very empathetic, and they feel things – they feel that discrimination, or they feel that they’re being treated differently, and they do react to that.”

“What we hear from our models’ families is this radically changes their self-confidence and their self-image in a positive way,” she continues. “Suddenly they’re participating in that class in school more or they’re talking to friends at recess, or if they’re older, they feel like they can contribute to a conversation with other adult friends in a meaningful way. It is a fabulous experience.”