Why Rick Guidotti turned his back on Cindy Crawford to challenge our perceptions of genetic diseases

Previously in the business of snapping supermodels, a chance meeting at a bus stop made this fashion photographer look again at young people affected visibly by genetic disease.

See a gallery of Guidotti's Positive Exposure pictures.

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.