I’m in a hotel in Seattle watching photographer Rick Guidotti at work. Amid high fives and shouts of “awesome” a group of young people are laughing and posing as he clicks away, capturing the wide smiles and infectious enthusiasm in the room. This is not an average photo shoot, however, and Rick is not your average photographer. Each of the young people has Costello Syndrome, a rare genetic syndrome, characterised by very distinct physical features, varying degrees of learning disability and an increased risk of cancer.

A few years ago, Guidotti was a successful fashion photographer, flying between New York, Paris and Milan working on high-profile campaigns for YSL, Revlon, Elle, Vogue and Marie Claire, photographing some of the most beautiful women in the world.

A chance encounter at a New York bus stop altered the course of his life and found him questioning what we actually mean by beauty. He had spent the morning photographing Cindy Crawford, and leaving the shoot he saw a young woman at a bus stop. She had pale skin and bright white hair, the traditional hallmarks of the genetic condition albinism. In Guidotti’s eyes she was stunning, and he set about learning more about the condition.

What he found left him shocked. Medical textbooks on the condition showed clinical pictures of patients with albinism, often photographed in their underwear, a black bar covering their eyes. There was no beauty in the pictures; they were dehumanising images of sadness, sickness and disease. They bore no relation to the beautiful young girl he had just seen waiting for a bus.

He contacted the US Albinism Society and persuaded them that by working together, genetic support group and fashion photographer, they could challenge perceptions of the condition and show the true beauty of people with albinism, a world away from the negative images of medical textbooks and media portrayals.

He decided to run the shoot in the same way he would run any fashion shoot, and as he worked he saw a change take place in front of him. Young people affected by albinism were coming into the studio with their heads down: years of bullying, teasing and feeling different had made a huge impact on their self-esteem. By photographing them in same way he would photograph supermodels, he witnessed the young people beginning to to lift their heads and embrace their difference, seeing their beauty. The images he shot appeared on the cover of Life magazine and Guidotti’s project, Positive Exposure, was born.

Guidotti now travels the world, attending conferences organised by genetic support groups. He photographs children and young people affected visibly by genetic disease and has created a bank of images that show the humanity behind the diagnosis; celebrating difference, and challenging us to think differently about what we understand by human beauty.

The philosophy of the project is “Change how you see, see how you change”. And this applies as much to the children and young people he photographs as to the doctors and geneticists treating them. Medical terms trip off his tongue with the same ease that he navigates the fashion world and his enthusiasm, New Yorker’s charm and genuine passion for what he does has made him a trusted friend in the rare disease community.

I first met Guidotti in Portland, Oregon in 2007 when he attended a conference organised by the Costello Syndrome Family Network, a group dedicated to understanding the very rare, so-called dysmorphic disease that affects my youngest daughter, Daisy.

Over the years, Guidotti has created a bank of images that really show our children’s personalities, a world away from the frightening artist’s impression images I was presented with by the geneticist who first diagnosed this condition in my own child. Guidotti has seen our children grow up, and has an easy rapport with them. His energy and enthusiasm is infectious and he is as comfortable in a room of children affected by a rare syndrome as he is in a room full of medical consultants.

He has now recruited many young people representing a wide range of genetic disorders to be ambassadors for change through his Pearls project, where they write blogposts about their lives and living with their diagnosis. He has also recently launched a new initiative called Faces Redefining the Art of Medical Education (Frame), a series of short filmed interviews with young people explaining how their condition affects them, aimed at educating the medical professionals treating them.

For Guidotti it’s simple: it’s about seeing the human being, not the disease or diagnosis. By showing doctors not just what they are treating, but who they are treating, he hopes to make them better healthcare providers.

And when society as a whole no longer sees children who look different as being in crisis, but as children having a life, then maybe they will be better able to accept them and see the humans beyond the disease.

You can find out more about Rick’s work at positiveexposure.org

Stephanie Nimmo is a disability advocate. She blogs at wasthisintheplan.com.