By ITV News Correspondent Rebecca Barry
When I meet Dani Ingrosso and John Else at the Trousseau Hospital in Paris, they are full of energy and positivity.
You wouldn't know they'd just driven for 10 hours from Chesterfield, in Derbyshire, to the French capital, with their severely disabled 19-month-old son Rudi.
He has Spinal Muscular Atrophy, a rare genetic condition, which affects his ability to move.
When he was diagnosed, aged six months, doctors said there was no treatment and it was unlikely that he'd live beyond two years.
John tells me: "You expect your child to have the chance to have a normal childhood and grow-up, then you're told that might not be the case anymore, that he might be around for very long, he's not going to start crawling and sitting up and walking and all the normal milestones, it's just horrible, horrible news."
But now a new a drug called Nusinersen can help children like Rudi get stronger and begin to move their limbs.
To get it, though, they've have had to travel nearly 500 miles.
Dani says: "We've had to come over to France to get a treatment - that actually they have access to in the UK - but we just can't get it, and it's just not fair.
"Before there wasn't anything, now there is something and it's available, it's out there, but it's out of reach for so many."
In Paris they have a team specialising in the procedure, which involves a series of injections.
Rudi's among nine British children who've travelled here to get it.
So far he's had four injections and physiotherapists say his strength has already improved.
His mum tells me: "Before he was literally like a rag doll he was so floppy and even little things like his feet are moving a little bit more than they did last week."
There are two hospitals in the UK - in Newcastle and London - that can provide this treatment, but they can only take a handful of patients who live locally.
John and Dani want it more widely available, for the sake of Rudi and other children like him.
"He is literally like a little ray of sunshine" says Rudi's tearful mum Dani.
"When we have our worst days, where you struggle with little things, Rudi's smile and actually having that hope for the future for him, keeps us going, because when you get told your child probably won't live until he's two, you can't even process it, you can't, you can't."
An NHS England spokesperson said: "We have every sympathy for these patients and families and are currently considering whether there is enough clinical evidence to go ahead with an interim scheme that would give access to Nusinersen, while NICE makes decisions over the long-term routine use of the drug."
For Rudi, that decision can't come quickly enough.