Owen Howkins, is one of only about 30 people in the world to have Schwartz-Jampel syndrome, which makes his muscles contract constantly and means he sometimes needs to use a wheelchair.
He was diagnosed when he was just two, after concerns that he couldn't crawl properly.
"His muscles don't ever relax and his balance is very poor, so he can't stand up unaided very well," the seven-year-old's dad Will explained on This Morning.
"He has a walking frame and wheelchair for longer trips out."
While the condition can be painful, when asked by Phillip if it hurt, the brave little lad simply said: "Not that bad. I do get stiff sometimes."
But for Owen, one of the biggest struggles has been feeling different from other children and not wanting to go out to play with everyone else - something which left him sad and lonely.
Then fate brought him a new best friend.
Thank you, Owen, for bringing in Haatchi - because we've all fallen in love with him!
Haatchi, an Anatolian Shepherd, had been abused as a pup and was just five months old when he was deliberately tied to railway tracks in north London. He was hit by a train.
But despite losing a leg and his tail, Haatchi was rescued and put up to be rehomed - just as Owen's dad Will and his partner Coleen were considering getting a dog.
"When I first locked eyes on him, there was something there that was different to any other dog that we had looked at," Coleen said.
"Because he was so different and was struggling with his mobility, there was just that connection there with Owen and I thought we had to give it a go."
And it seems Owen and Haatchi were destined to best buddies, with the pair proving inseparable. Well, almost.
Haatchi is also a trained therapy dog, helping other sick people when he goes off to "work" at local hospitals and other centres.
Describing the first time the caring canine went to visit a poorly patient, Coleen explained: "The staff and the parents almost got more than the children.
"It gave them five minutes' relief from their working environment and it gave the parents five minutes' relief from worrying terribly about their children.
"Just stroking him, the whole ward ... the whole atmosphere completely changed. It was quite phenomenal to watch."
But Owen doesn't mind sharing his best friend, since he's the one who has Haatchi waiting patiently for him when he gets home from school.
He'll sit on the sofa and chat away to Haatchi - Haatchi will lie behind him on the sofa while Owen's working away, doing his homework.
Will Howkins, Owen's dad
And now the little lad has much more confidence. Despite his mobility issues, he loves going for walks with Haatchi and especially taking him to dog shows.
Owen's dog has already been honoured at the House of Lords with an International Fund for Animal Welfare award - presented by Queen legend Brian May - while, next month, a prestigious Crufts award could be on the cards.
Haatchi has been nominated in the Friends for Life category, which looks to reward dogs who have truly earned the men's best friend title, through bravery, support or companionship.
According to Owen, his very own friend for life definitely fits the bill!