Life Video

By Dan Coles


A little boy who had forgotten his parents after suffering from a rare type of childhood dementia can now recognise them again – after he has begun a pioneering medical trial that implanted a chip in his head.

Little Harley Bond, five, was diagnosed with Sanfilippo syndrome when he was three years old, a rare type of dementia that causes permanent brain damage.

His parents Wayne Bond, 47, and Emma Siddal, 38, from Sheffield, were heartbroken when Harley lost the ability to recognise them and stopped saying ‘mummy’ and ‘daddy’.

But after he was enrolled on a new clinical trial at Great Ormond Street Hospital, they were thrilled as both his speech and ability started to improve – and he can recognise them both.

The trial, which is still underway, involves a chip implanted into Harley’s head that releases small quantities of the enzyme that is missing that causes his symptoms to get worse.

And although his parents still say Harley has some bad days, they are thrilled that the treatment appears to have stopped his condition worsening – and has given them more precious time with their little boy.


Mum Emma, a full-time carer said: “It was heart-breaking in the months he couldn’t recognise us, he struggled to make eye contact with us, and didn’t call us mum and dad.

“The trial is doing well, and it’s really giving us a little bit of hope for the future, getting on it was potluck and we’re happy he is responding well.

“We realise, however, that it won’t cure him, but it might give us a few extra precious years with our brave son.

Harley was diagnosed with Sanfilippo Syndrome type B, in 2016.

Despite him developing well in the first few months of his life, his parents started to worry as he kept getting infections and colds, and his speech started to go backwards when he was three.

They were devastated when medics told them Harley was suffering from a life-limiting condition, and his symptoms soon began to worsen.

Little Harley would stop breathing momentarily during the night, after developing sleep apnoea as a result of the condition – and as he lost the ability to know what was safe to eat, his family had to look after his as though he were a baby, trying to eat plants, bushes, and rocks.

But after hearing about a clinical trial, Harley’s family put him forward for the experimental treatment in 2017 – and say he is doing well.

Dad Wayne said: “He was born completely fine and developing well, but then everything changed.

“He was really boisterous with other kids and his nose was always runny, he kept getting infections and started to lose his speech.

“When he went to the park, or was with other kids, we knew there was something up because he just didn’t act like everyone else, he was really boisterous.

“He couldn’t remember simple things like knowing how to use the toilet or what was food and what was not.

“The hospital spoke to us about option and let us know about this new trial, but they told us he would need to do a year of studying to assess his memory.

“Luckily his memory was good enough to be able to get onto the trial, he could remember enough of what he was told to show there was hope he could be saved.

“It was going well but then he had a bad patch for a few months, he didn’t know who we were and couldn’t even call us mummy or daddy, the whole thing is soul destroying because we’re looking at our little boy and he’s dying.

“We try to do everything we can to stay positive and being mentally positive is the hardest part, kids with this syndrome don’t make it to adulthood so we know we just have to enjoy the time we have with him.

“Knowing that our son has dementia was hard to even comprehend, but that’s why it’s so important that everyone starts to know that it is possible and that it isn’t just older people this disease can effect.

“With the clinical trial he is on, he has good days and bad says but naturally this condition is supposed to just get worse and worse, which isn’t the case with Harley, sometimes he’s completely in control of himself but other days he can’t move.”

The trial is being offered by US pharmaceutical companies and is an enzyme replacement therapy which delivers the missing enzyme directly to the brain thus bypassing the blood-brain barrier.

The CEO of one drug giant Allievex, which is one half of the firm running the trials, Thomas Mathers, explained: “In general Sanfilippo is a disorder, and in these children, they have a genetic mutation which stops them from being able to produce a certain enzyme that they need otherwise their neurons will be killed off.

“We have a device that is implanted into the child’s head which releases a synthetic version of the missing enzyme directly into the brain that washes the sugar build up which causes the neurons to be killed.

“Worldwide, we have 22 children who have used or are using this trial.”

Harleys treatment is completed at Great Ormond Street hospital, they facilitate the device, track his progress and keep on top of his condition.

Harley still suffers with a multitude of difficulties but hasn’t let it get in the way of him being a kid.

Wayne said: “When you watch him go through all of this, he seems invincible – he rarely complains about any of it.

“We have good and bad days, but we’re cherishing the time we have with him and hopefully the treatment will work, and we’ll have him for many more years to come.

“Sometimes he forgets who we are and it’s awful, but we always remain strong and it’s made our family a unit of strength because we have been through it all and remain resilient together.

“Before the trial started, Harley was just getting worse but since he has been on it, he has remembered words he could no longer say, he recognises us as mum and dad and the condition seems to of stabilised.

Emma said: “We are so proud of everything out little boy is achieving, we thought he would just get worse but he seems to be improving very slightly in some cases.”

Wayne added: “He’s such a strong lad, and he gives us glimpses of his personality when he can, which we love.”