Nicola and Graeme Swan are watching their son slowly die before their eyes.
James Swan was an otherwise healthy three-year-old boy in July last year.
The Wellington boy, who turned 5 this month, was just a bit slower at running than his older brothers, Oliver, 7, and Marcus, 9.
But July 1, 2016, was the day he began to take his last steps.
He is believed to be the only person to be suffering from a condition that remains undiagnosed, despite samples being sent for testing in Australia, the United States and the United Kingdom.
"We used to go outdoors and walk bush tracks and James would always be saying 'pick me up and carry me, I don't want to walk'. And we're like 'come on, you've got two legs, there's nothing wrong with them, you're walking'. So I feel guilty now, it's like 'oh my God, there was something wrong'."
James continued to moan about walking and soon began crawling up stairs. However, again, they thought it was just childhood behaviour.
It wasn't until they were approached by staff at his kindy, Bellevue Kindergarten in Newlands, to say that he had stopped climbing everything and could no longer walk in a straight line, they knew it was serious.
"At which point I picked him up and took him straight to the GP, thinking brain tumour.
The GP said go home, pack a bag, you're going to be there for a while, be prepared for this to be a brain tumour."
It was initially thought he had Duchenne Muscular Dystrophy, but that was quickly ruled out.
He deteriorated quickly in hospital, losing 1.8kg in his first eight days.
"He stopped eating and no one could work out why because before that he just ate everything."
They would later discover the muscles in his stomach were no longer strong enough to do their job. He has been tube fed ever since that first hospital stay.
"He's still undiagnosed. He presents like an adult who has motor neurone disease mixed with a child who has got SMA [Spinal Muscular Atrophy]. He doesn't actually have either of those conditions but the way he presents are similar to those two."
Over the last 16 months, James has slowly lost the ability to stand, talk, eat, do bowel movements or even swallow saliva.
"He can't stand at all now. Four months ago he was in a wheelchair but could still stand and slightly balance. He can no longer do that. He can't walk. Crawling is becoming near impossible because his arms will collapse on him.
"He's desperate to walk. Every single day he will say to me, 'mummy my legs don't work, but they might tomorrow'. So it's really hard."
Despite his rapid deterioration and terminal diagnosis, Swan said her son still remained upbeat and positive and took everything in his stride.
"He lights up the hospital room. He's got such a horrible condition and they can basically see him dying in front of them, yet he continues to smile through everything. He does not scream when he has procedures, he just carries on like this is completely normal."
His condition has also affected his autonomic system - part of the nervous system that regulates bodily functions.
"His heart rate can go from 160bpm two seconds later it could be 50bpm. It's not regular and his body doesn't regulate his temperature which gives you circulation problems.
"It's kind of like watching a body slowly shut down and there's nothing we can do to stop this.
"[Wednesday] I got a phone call saying 'his heart rate is dropping so low we think you need to ring your family and tell them that this could potentially be his last Christmas and make sure everyone is around'.
"I just live and hope that he can stabilise a little bit and give us time to try and find somewhere in the world that might have something that could help him."
The fatigue is also getting worse.
"We used to be able to take him out for a drive, but he doesn't want to leave home now. He just lies on the couch. He's too tired. The fatigue levels are extreme."
Despite being repeatedly turned down for funding to help with home modifications from Government-funded disability support organisation, Enable, the family had been blown away by the support from a couple of generous local businesses.
Brent and Jeanette Tuohy of Tuohy Homes have carried out critical renovations to the family home, while Precision Concrete built a new concrete ramp into their home.
The couple had been struggling to survive on one income after she had to quit her job on that day of July 1, last year.
"We have weeks where we rely on people giving us food. There is nothing more demoralising as parents than saying to your kids 'can you please stop eating we need that to last a week'."
A Givealittle page has been set up to help for James' "bucket list", which includes a helicopter and hot air balloon rides and a family trip to Queenstown where they lived briefly previously, and everyday expenses.
Anyone wishing to donate to the Swan family can head to: https://givealittle.co.nz/cause/bucketlist4james
The 19-year-old was found in a remote area in the hills of Upper Hutt.