A five-year-old dementia sufferer who forgot his parents recognizes them after a groundbreaking treatment.
Harley Bond, of Sheffield, was diagnosed with Sanfilippo syndrome in just three.
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The rare disorder causes the brain to "fill with waste", which can lead to irreversible damage, according to Sanfilippo Children & # 39; s Foundation .
Harley's parents Wayne Bond, 47, and Emma Siddal, 38, were destroyed when their son no longer knew who they were, and ended up saying "mom" and "dad." [1
Without cure or treatment, the kid was treated to a clinical trial at Great Ormond Street hospital (GOSH) that implanted a chip in his brain.
The chip releases small amounts of an enzyme missing in Sanfilippo patients.
Gradually, Harley's speech began to improve, with him now crying out for his parents.
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Sanfilippo syndrome affects about one in every 70,000 children," Sanfilippo Children's Foundation statistics show.
The inherited disorder interferes with one of the chemical reactions that should occur naturally in the body.
This occurs due to a missing enzyme that normally breaks down and recycles a large sugar molecule called heparan sulfate.
Sanfilippo is considered a form of childhood dementia, with symptoms including loss of speech, severe hyperactivity, insomnia, lo ss of mobility, heart problems, seizures and premature death.
Harley's parents first became concerned when he was only a few months old.
"He was born perfectly well and developed well, but then everything changed," Bond said.
"He was really funny with other kids and his nose was always running, he kept getting infections."
When he turned three, his numbers started to deteriorate.
Harley was later diagnosed with Sanfilippo syndrome type B 2016.
The condition was four subtypes – A, B, C and D – depending on which enzyme is missing.
The progressive condition caused Harley to develop sleep apnea, which led to him not breathing during the night.
He would later try to eat plants, shrubs and stones.
"He couldn't remember simple things like knowing how to use the toilet or what was food and what wasn't," Mr Bond said.
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Doctors from GOSH came in contact with Harley's parents to suggest he signed up for an experimental treatment.
"The hospital talked to us and told us about this new ordeal, but they told us he would have to spend a year studying to assess his memory," said Bond.
"Fortunately, his memory was good enough to be able to enter the trial.
"He could remember enough with what he was told that there was hope that he could be saved."
Although the trial is going well, Harley's condition temporarily took a turn for the worse.
"He had a bad note for a few months, "Mr. Bond said.
" He didn't know who we were and couldn't even call us mom or dad.
"The whole thing is soul destroying."
Miss Siddal, who takes care of Harley full time, added: "It was heartbreaking in the months he could not recognize us. He struggled to make eye contact with us. "
Despite the setback, Harley responds well to the implant overall.
"It gives us some hope for the future," Bond said.
"We realize it won" Cure him, but it can give us some extra valuable years with our brave son. "
The expectation for a Sanfilippo patient is between 10 and 20 years, according to Team Sanfilippo Foundation .
"With the clinical trial he is on he has good days and bad sayings," said Mr. Bond.
"Of course this condition is supposed to get worse and worse, which is not the case with Harley, sometimes he has complete control over himself but on other days he can't move. "
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Despite everything he has endured in many ways, Harley is like all other young children.
"When you see him go through all this, he seems invincible, he rarely complains," said Mr Bond.
"He is such a strong boy and gives us glimpses of his personality when he can, which we love."
The couple works hard to stay positive despite adversities.
"We have good and bad days, but we value the time we have with him and hopefully the treatment will work, and we will have him for many years to come," Bond said.
"Sometimes he forgets who we are and it's horrible, but we always stay strong and that has made our family a unit of strength because we have gone through everything and remain elastic together."
Miss Siddal added: "We are so proud of everything our little boy does, we thought he would only get worse but he seems to improve very little in some cases."
The couple speaks to raising awareness of dementia in children.
"Knowing our son has dementia was hard to understand, but that is why it is so impor- tant. Everyone is beginning to know that it is possible and it is not just older people who can suffer from this disease," says Mr Bond.  The trial is being offered by two US pharmaceutical companies.
Thomas Mathers, CEO of the drug giant Allievex – one of the companies conducting the trials – added: "These children have a genetic mutation that prevents them from producing a certain enzyme that they need otherwise their neurons will be killed.
"We have a device implanted in the child's head that releases a synthetic version of the missing enzyme directly into the brain that washes the sugar build-up causing the neurons to be killed.
" All over the world we have 22 children who have used or are using this trial. "