Ohio mom reveals 'heartbreak' after son was diagnosed with DEMENTIA at age EIGHT - as she shared the subtle symptom that led to the 'nightmare diagnosis'

An Ohio mom has revealed her 'heartbreak' after her eight-year-old son was diagnosed with a rare disease that will lead to childhood dementia.

Grayson Naff was diagnosed with Batten disease last year - a group of rare genetic conditions that cause the brain to gradually shut down over five to ten years.

His mother, Emily Blackburn, from Tipp City, said: 'This is what heartbreak is. The pain is beyond words. There are times I have trouble breathing through this nightmare.'

Batten disease affects about one in 25,000 babies and eventually sufferers lose the ability to speak, move, see and swallow. They usually live for only five years after symptoms begin. 

Grayson's eyesight has already deteriorated to the point where he is considered legally blind, meaning his is already struggling with daily activities like playing, reading and writing difficult.

Grayson, 8, with his mother Emily Blackburn

Grayson with his mother, her husband, Chris Naff, and his younger brother Beckett. Siblings of the affected children have a one in four chance of also developing the disease, and a 50 percent chance of being a carrier, according to Boston's Children's Hospital

'If there is no approved treatment/cure in the coming years Grayson will lose every function he has now, the first being full blindness,' his mother said. 

Grayson recently started training with a white cane - a mobility tool for the visually impaired. 

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His mother, Mallory, who prefers to keep her full name anonymous, was born without a uterus, making her infertile and fully diminishing her chances of conceiving a child naturally. 

It involves walking with a cane which scrapes along the ground as the person walks, allowing the individual to detect obstacles in their environment.

At best, he can see about five to 10 inches ahead of him, Mrs Blackburn told Fox News.

'Accepting that my son is legally blind — and that if he goes down the typical path of Batten disease, he will likely lose all of his vision — is heartbreaking,' she said.

Grayson's health problems began in late August 2022 when he began standing close to the TV to see it.

His mother took him to an ophthalmologist, who noticed an issue in the boy's retina and referred him to a specialist at the Cincinnati Eye Institute.

The specialist thought it could be Stargardt Disease, a rare genetic eye disease that causes vision loss in childhood.

But after genetic testing to confirm the diagnosis, doctors realized he in fact had Batten disease.

It is passed down through families and is caused by a genetic mutation. There is no cure for the disease.

Because Batten disease is recessive, children must have two copies of a mutation - one from each parent - to be affected. 

Siblings of the affected children have a one in four chance of also developing the disease, and a 50 percent chance of being a carrier, according to Boston's Children's Hospital.

Grayson takes Miglustat, a drug which is hoped could ease or slow down symptoms.

But the drug is not yet FDA-approved for Batten disease, meaning if insurance does not cover it, the medicine costs the family around $100 per pill or $9,000 every month.

Grayson has also started to learn Braille, which allows blind people to read by feeling a pattern of raised dots.

At school, he has a scribe who notes down what the boy says. A portable desktop magnifying device which magnifies and changes contrast also helps he read his papers at school.