THE parents of two children with a rare genetic disorder are campaigning for a drug that would ‘transform’ their lives to be licensed in the UK.

Nick and Denise Williams’ son and daughter, Jack and Emily, who live in Grange-over-Sands, were both born with phenylketonuria (PKU), an illness that strictly limits the amount of protein a person can process.

Those with the disorder experience a build up in their body of the amino acid phenylalanine - a natural substance found in protein - which cannot be broken down and builds up in the blood and brain. This can lead to brain damage if undetected.

“A mother gives birth to a beautiful little baby,” father Nick explained. “The first thing a mother does usually is breastfeed, which is very high protein. If they’ve got PKU and it’s not detected, the sad thing is what that they are actually doing is killing the baby or certainly damaging the brain.”

Fortunately, Nick and Denise’s children were tested at birth, meaning both could immediately be placed on the special diet.

But as 12-year-old Jack gets older, Nick said that his son, who is a keen footballer and athletics competitor, is struggling to keep up with his peers.

“He’s big into sport and football and athletics,” Nick said. “He’s got some skilled mobility but he’s already starting to go backwards now because he’s not able to have the energy levels and his body can’t physically do what he would want it to do.”

However, there is a drug on the market that is used in both Europe and the USA that has the potential to significantly improve Jack’s quality of life.

Kuvan is a synthetic form of a natural substance that activates an enzyme needed to break down phenylalanine in the body.

Emily, Jack’s 10-year-old autistic sister, is on a clinical trial of the drug.

“We got Emily on to a trial and we know it works,” Nick said. “She’s responded and it means that we have to deal with the autism but not the food problem. She only has it until she’s 13 and then they take it off us.”

Westmorland and Lonsdale MP Tim Farron has got behind the Williams’ campaign, writing to both NHS England and the National Institute for Health and Care Excellence (NICE) as well as bringing the issue up in Parliament.

Mr Farron accused the health authorities of ‘buck-passing’, claiming that both organisations said it was the other’s responsibility to license the drug.

“It’s inexcusable that we are one of the only countries in Europe that are denying access to Kuvan,” Mr Farron said. “Rather than a postcode lottery, people suffering from this condition are suffering from an international lottery and the country in which you reside dictates whether you will be able to access this drug.”

And a group of MPs, including Penrith and the Border’s Rory Stewart ,pledged to raise awareness by following the PKU diet for a day. Participants were required to adopt the diet of someone with PKU by only consuming approved foodstuffs and no more than 10g of protein. Mr Stewart said: “Today was an important and powerful experience that clearly demonstrated the difficulties faced and sacrifices made by those who suffer from PKU. The challenge was extremely challenging, making it all the more informative.”

A NICE spokesperson said: “At the request of NHS England, NICE has been asked to look at Kuvan as part of its topic selection process. The topic is scheduled to be discussed in September. If there is consensus with all decision makers, work will begin on the appraisal.”