The mum of a five-year-old girl with a terminal genetic disorder has said her daughter’s health is likely to deteriorate quickly if the NHS removes provision of the vital drug which is “keeping her doing”.

Two years ago, Beatrice Cieslik was diagnosed with CLN2 type Batten disease – a rare degenerative condition which causes seizures, blindness, dementia, and difficulty with mobility and speech.

She is currently treated with the drug Brineura, allowing her to attend school and live “a better quality of life”.

NHS access to the drug is set to end in May, but the National Institute for Health and Care Excellence (NICE) described talks with NHS England and developer BioMarin as “constructive”.

Beatrice’s mother, Anna, from Doncaster, said: “Not only have we got to live with our child having a life-limiting illness, but the drug that’s keeping her doing all these things may be pulled.

“Without it, she will deteriorate quite quickly.”

Since 2019, Brineura has been provided for eligible NHS patients under a managed access agreement, with that access extended in October 2024.

The life expectancy for a child with the Batten disease, without any treatment, is 10-12 years old.

“You don’t look forward to things. Birthdays are meant to be enjoyable but for us it’s one year closer to death,” said Anna.

“There is no alternative whatsoever. There is no cure, and it comes down to money – but how much is a child’s life [worth]?”

NHS England confirmed data was being collected to determine whether the drug was “clinically and cost-effective”.

Brineura, or cerliponase alfa, is the only approved treatment for the disorder.

According to NICE, a fortnightly, 300mg dose of Brineura costs £522,722 per patient annually.

Anna said Beatrice is currently living a normal life “with just a bit more support” thanks to the prescribed drug.

“It is not a cure – and this is the heartbreaking thing. [But it gives] a better quality of life than she would usually have,” she said.

“The child we see is happy and chatty, and we never take that for granted, ever.”

It is estimated that CLN2, which is the only type of Batten disease treated with Brineura, affects between 30 and 50 children in the UK.

The drug infusion works by restoring enzyme activity in the brain which is absent due to a genetic error. This means damaging products are removed, which slows the onset of deterioration and disability.