It is a scene of domestic mayhem you might see at any family home in middle England. With the school day over, five-year-old Dylan can't wait to chase his little sister Mia through their Victorian terraced family home. As the children shriek uproariously, their parents, Jill and Iain Kelly, laugh indulgently at their antics.

Yet behind the laughter and the smiles lies a heartbreaking confession. For the truth is that had Jill and Iain understood how desperately ill their little boy would be, they would have opted for a course of action that many still find unthinkable. They would have terminated the pregnancy.

'I love my son. He's changed our lives,' Jill says. 'But if I'd known everything that Dylan would have to go through, and will have to go through, there's no doubt in my mind that, given the correct information, I would have asked for a termination.

Dylan Kelly, five, needs round-the-clock care and his parents say they regret not having an abortion because of his problems, pictured with his sister Mia, three

'I'm adamant about that. And it makes me feel guilty just saying it because Dylan is my world. I love him, he's an amazing little boy.'

Born with severe micrognathia, a condition that causes an undersized jaw and acute breathing difficulties, Dylan needs round-the-clock care.

He has a permanent tracheostomy, is fed nutrient-rich milk through his stomach, has slurred speech and a deformed right arm.

Sitting at Jill's side, husband Iain nods in agreement. 'We made it clear to the doctors that we didn't want a child who wasn't going to be able to ride a bike and do things that normal children do,' he says.

Dylan's parents, Iain and Jill Kelly, were forced to leave their jobs to care for their son and they have now been declared bankrupt

Jill interrupts. 'It sounds awful, doesn't it? I would hope that people would look at the whole story and the whole situation before they make a judgment. Nobody knows how they will feel until they're in that situation.'

The fact is that the Kellys' lives have been shattered.

Forced to leave their jobs to care for Dylan, they have been declared bankrupt and have now lost their home. They get through the weeks and months with the help of anti-depressants. They are furious that – as they see it – the Royal Victoria Infirmary (RVI) in Newcastle failed to tell them how gravely disabled Dylan would turn out to be, and what consequences would follow.

Only now have they abandoned a five-year legal battle to get justice from the NHS. They simply don't have the money to continue.

As for Dylan, he suffers constant stress, has endured endless hospital visits and operations, and may have a tracheostomy tube for the rest of his life.

Iain, 30, and Jill, 31, from Sunderland, met online in 2005. They married in 2008 and were delighted when Jill became pregnant.

During a 20-week ultrasound scan, the sonographer noticed that the baby's long bone in his right arm was on the bottom end of the growth scale. Another scan a few days later revealed Dylan could have radial club hand, a condition that causes the hand to point towards the body, and Jill was referred to the RVI.

WHAT IS MICROGNATHIA? Micrognathia is a term for a lower jaw that is smaller than normal. In some cases, the jaw is small enough to interfere with the infant's feeding. The problem can be caused by certain inherited disorders and syndromes. Micrognathia is can cause the teeth not to align properly and it can result in breathing problems. Children with this problem should see an orthodontist when the adult teeth come in. Because children may outgrow the condition, it often makes sense to delay treatment until a child is older. Advertisement

She recalls: 'I couldn't sleep or eat. It sounds awful, but I didn't want a baby with disabilities. I was thinking, 'Is he going to be in a wheelchair? Am I going to lose my job and be a stay-in parent?'

It wasn't what I wanted for myself at the time.' At the RVI, Jill had a more in-depth scan and an amniocentesis test. One of the consultants mentioned that the baby had a small jaw, but Iain and Jill say micrognathia wasn't mentioned. The main issue was that his arms and wrists appeared to be fixed in position.

Jill says: 'When I say it out loud it sounds terrible, but I didn't want to bring a baby into the world that was going to have a sub-standard life.'

The couple made the agonising decision to terminate the pregnancy. When they explained their wishes to the consultants, they were advised that it was too early to make a 'rash' decision.

During the next two months they had several more scans. The results from the amniocentesis were fine and chromosome tests came back normal. They were told the baby's heart was normal, they were reassured that a kink in Dylan's spine was minor, and that the problems with his arm could be fixed with surgery.

The micrognathia had appeared on the scan notes as a potential problem, but Iain and Jill say the consultants never explained verbally to them the condition or what it would mean for Dylan's quality of life.

Ultimately it was decided that the chances of Dylan having the condition looked 'less convincing'.

Iain and Jill say they were left feeling reassured. 'We knew we were going to have a baby with a bad arm and bad hand, but that was it,' Iain says.

Dylan was born at Sunderland Royal Hospital in July 2009 by emergency caesarean section. He was tiny, weighing just 3.4 lb.

Doctors discovered he had severe micrognathia and a large tongue, which was tucked down his windpipe, preventing him from breathing. He was blue and floppy and was rushed to theatre for an emergency tracheostomy. 'The surgeon came to get consent to put a tracheostomy in and said it wasn't looking good,' Jill says. 'I thought Dylan was dead. I remember discussing funeral arrangements with my dad.'

Dylan pulled through but it was found that as well as the micrognathia he had a cleft palate and a hole in his heart. He was very small and had the deformity in his right arm – and both conditions were deemed signs of Baller-Gerold syndrome, a rare genetic disorder.

The couple are furious and claim the Royal Victoria Infirmary (RVI) in Newcastle (pictured) failed to tell them how gravely disabled Dylan would turn out to be, and what consequences would follow

Before they could take him home, Iain and Jill had to perfect several procedures to care for Dylan, including learning how to suction-out his tracheostomy several times an hour.

Despite the trauma of Dylan's arrival, Jill soon found she was desperate for a second child. 'My body craved a normal child,' she says. 'To give birth, hold the baby and breast-feed – all the stuff I missed out on with Dylan.'

I ask if they would have terminated Mia, now three, had she shown abnormalities. They both nod their heads. 'I wouldn't want to put another child through what Dylan has been through,' says Jill.

Until Mia was born, Iain worked a 40-hour week as a computer technician for Siemens. But he left the job to help Jill care for Dylan and the new arrival. Jill had already quit her job at Barclays Bank. Before long the debts were piling up – the family had to forfeit their home and are now renting a four-bedroom house.

Feeling they had not been given the full picture of Dylan's disabilities, Iain and Jill decided to launch a claim against the NHS.

Two weeks before the court date, which had been set for last Monday, their law firm, working on a 'no-win, no-fee' basis, dropped the claim, saying the couple didn't have a strong enough case.

Jill says: 'For us, it was never about the money, it was about justice. I've got no idea where we go from here. We have no pensions, no money, no house and no job prospects. But we love our son. He's amazing and we're going to give him the best life we can.'