He sounds like the kind of boy any parent would dream of – a boisterous type who never cries when he suffers a bump or scrape.
But life for Dexter Cahill and his parents Lindsay and Tom is actually fraught with danger because he never feels any pain due to an incredibly rare genetic disorder– even if he incurs a serious injury.
Dexter, who will be four next Saturday, has already suffered several fractures. They include a broken thumb and hand, and a shattered first metatarsal bone in his left foot three weeks ago.
But often his parents don’t even know how they happened.
Earlier this year during a dance session at nursery, his teacher played a song about the alphabet. When it reached the letter D, Dexter jumped up and down so enthusiastically he couldn’t get up again afterwards. There were no tears, or screams of agony but it turned out he had broken his shin bone.
His GP mother Lindsay recalled: ‘His nursery rang me and I rushed in, crying all the way.
‘I expected Dexter to be upset but there he was, holding court with numerous staff gathered around him as he asked the paramedic what was in his medical kit.
‘”Hi, Mummy!” he said as I knelt beside him. He’d broken his left tibia, but he didn’t need any morphine at hospital. They set the bone and cast the plaster without it. All Dexter wanted was a lollipop.’
Scientists say the chances of a child inheriting Dexter’s disorder – hereditary sensory autonomic neuropathy type four – are one in 125 million as both parents have to carry a rare faulty gene. Lindsay, 34, and husband Tom, 35, an engineer, first feared Dexter had a problem at four months when he began teething and would rub his tongue against his teeth until it bled. He has since pulled out three of his teeth and suffered countless minor cuts, scratches and bruises.
As a toddler, he would stare at his parents in bafflement as they fussed over him when he fell over.
Last summer, Dexter was happily splashing about in a paddling pool when his young cousin dipped her toe in the water and screamed at how cold it was. Only then did the family realise Dexter was sitting in water so cold he could have developed hypothermia. It took 18 months of tests to finally diagnose the youngster’s condition.
Lindsay said: ‘People think Dexter is a superhero. But he’s fragile. He may suffer appendicitis one day and won’t know about it because there will be no pain.’
The couple have been forced to move from their home in Bristol because of its potentially dangerous nooks and crannies and now live in a modern open-plan property. Sharp edges are clad in foam and air conditioning has been installed as Dexter is not able to know if he’s too hot or too cold.
Lindsay’s hope is that when he reaches adulthood he will be able to fend for himself but admitted ‘there will be plenty of injuries along the way’.
‘He has to learn not to hurt himself, even though hurting himself does not hurt,’ she said.