A cheeky smile spreads across Ethan Moss’s little face as he undoes the laces of his dad’s trainers while he is sitting on the sofa talking.

“He’s so lively and inquisitive,” says Nick, as he looks fondly at his fair-haired, two-year-old son.

“It’s very difficult to see him looking so healthy and normal, when we know that inside him there’s a medical mystery that could affect his life and ultimately kill him.”

Ethan is one of just 500 children in the world suffering from a condition called lymphangio-matosis, which causes malfunctions in the lymphathic system – the body’s drainage system – resulting in cysts and benign tumours growing on and within the internal organs, causing extreme pain, impairing organ function, and causing premature death.

Inside Ethan’s small body, dozens of cysts are growing: inside his left lung; on his oesophagus; and the pulmonary artery that carries blood from the heart to the lungs. Ethan is oblivious to all this. His attention has moved on from the laces on his dad’s trainers, and he has begun to investigate his watch with the curiosity typical of a two-year-old.

“Ethan doesn’t know he is ill, although he’s becoming more aware about his hospital appointments,” says 39-year- old Nick, a former soldier in the Royal Greenjackets.

“When he was a baby he was sedated for tests and anyway, he was too little to understand what was going on, but he got very upset at his last tests about having to have a mask put on his face so he could be sedated.”

Nick continues: “He doesn’t know he’s ill. But Ethan knows he’s special. He sees his photo on my T-shirt and on the side of my trailer. He probably feels like he’s a celebrity!”

Ethan’s happy little face is becoming well-known around his home town of Winscombe, North Somerset, and also in nearby Weston-super- Mare, as his dad Nick and mum Kelly have embarked on a campaign to raise funds for research into lymphangio- matosis (LGD), and to raise awareness of the condition – and to fund a trip to America for Ethan to be assessed by a specialist in LGD.

Later this month, people all over Britain will hear about Ethan, as Nick will be setting off on a gruelling 42-day, 1,500 mile military-style march around the country, carrying a huge 50lb army rucksack known as a Burgen.

“Raising awareness is as important to us as the money,” says Nick.

“We want to have an impact on many lives, not just Ethan’s, but also other families and other children.

“Conditions like this need to be understood better.”

Nick and Kelly, a former hairdresser, knew there was something wrong with Ethan before he was born, after a routine 20-week scan revealed there was something wrong with his chest.

Kelly recalls: “It seemed like a normal pregnancy, but then at the 20-week scan they found an abnormality in his chest.

“I had to have regular scans to make sure he was growing as he should, but they could only see the right lung.

“They thought there was only a 50-50 chance of survival, even if he survived the pregnancy. After he was born they put him into an incubator in the neonatal intensive care unit in Bristol. He couldn’t be fed for a week, he was just tube fed liquid until they knew the situation with his stomach.

“He weighed eight pounds seven ounces when he was born, and he was surrounded by all these tiny premature babies while he looked so healthy and so cute.”

Ethan underwent a barrage of tests at Bristol Royal Infirmary including X-rays and a CT scan with a dye injection, to see if food and drink were being digested properly.

Nick says: “After those tests they could see his digestive system was working properly, and we were allowed to start feeding him and he came out of the special care baby unit. Then after another week in hospital we were able to bring him home. He seemed like a perfectly normal baby, although we knew they were still concerned something was growing in his chest area, and he had to go back for more scans and tests.

“Even so, it came as a complete bombshell when seven months after we had taken Ethan home from hospital we returned for what we thought was a routine appointment with the consultant, and we were told he had lymphangiomatosis. We knew there was something wrong, but he looked so well so we hadn’t been expecting anything like that. We went in for a 10-minute appointment and got told he had this condition. It just seemed surreal. We were in total shock. We just drove home in silence.”

After they came to terms with the shock of Ethan’s diagnosis, Nick and Kelly decided to do all they could to try to find a cure.

Nick explains: “We couldn’t just sit there and do nothing. We wanted to be very proactive.

“We were sitting at home trying to think of solutions. First we wrote to 21 specialist hospitals asking for their advice, telling then we’d had this diagnosis and did anyone know anything and would they be willing to speak to us.

“A consultant in Birmingham gave us advice on things to watch out for, such as if Ethan developed a high temperature or fever, but just about everything we know we have researched ourselves.

“We’ve been told an operation is too much of a risk because they don’t know much about surgery for this sort of condition, and they wouldn’t be able to remove all the cysts, and it could make the condition more aggressive if they disturbed the cysts.

“At the moment there’s nothing they can do to slow it down. There are trials taking place at a hospital in Ohio in America, where a couple of children are apparently responding well and the growth of the cysts is being slowed down. Our consultant has given us copies of Ethan’s scans to send to the consultant in America. We’re desperate to get Ethan over there because if the treatment would work for him as well, then it could give him a real chance, although apparently it doesn’t work for everyone and there are some side effects.

“Children with this condition are supposed to live until they are about 10 years old, give or take a couple of months, so unless we can do something now it will get to the point of no return because so much damage will have been done to his internal organs.”

Kelly explains the cysts are presently growing in proportion with Ethan’s body, but as his growth slows down as he gets older, the cysts will be growing at a relatively faster rate.

“That’s where the serious problems will begin,” she says. “It seems to be worse if the cysts are in the chest and torso area, which is where Ethan’s are. One family we know with a child who had cysts told us how they started leaking into the chest, and the fluid hardened inside the body.”

Already the cysts in Ethan’s body have increased in the time that has passed between his most recent scan and the one before that. Nick shows me a copy of an X-ray, which shows a blurred area in the upper lobe of Ethan’s left lung.

“Those are cysts, there are 10 to 15 cysts clumped there, and more have grown since this X-ray was taken,” he says. “We found out they’d spread a few months ago when Ethan had a routine MRI scan.”

He adds that there is no obvious reason why Ethan has lymphangiomatosis.

“It’s not a genetic condition. We have seven children between us and the others are all healthy,” says Nick, who has a nine-year-old daughter, Freya, from a previous relationship, while Kelly has four children – Gemma, 13, Josh, 12, Amy, 10, and Ellie, aged eight – from a previous relationship, and they also have Ethan and his younger brother Tommy Lee, aged seven months.

“We’ve asked ourselves all the questions, and wondered ‘Why us? Why Ethan?’ “But there are no answers.”