Like any loving parents, Barry and Kate Hartin want nothing but the best for their children.

In their case it means taking their little boy Daniel across the Atlantic for an operation to help him move about more easily.

The Hartins are among a growing number of families finding themselves having to fundraise to get their loved ones the treatment they need because it is not available on the NHS.

Those making the decisions on whether to approve funding for operations, nationally and locally, have to juggle effectiveness, how vital it is, the cost of the treatment and how successful it is likely to be.

With such huge demands on the NHS budget, there are times when difficult decisions have to be made, and families find themselves having to look elsewhere.

Daniel Hartin, from Haywards Heath, and his twin sister Alice, were born three months prematurely in May 2011 at the Royal Sussex County Hospital in Brighton.

Alice recovered well but Daniel was diagnosed with cerebral palsy, meaning he has suffered irreparable damage to some of his brain and he is unable to walk or stand unaided.

The situation for the youngster will only get worse as his muscles will tighten as he gets older and he will eventually end up in a wheelchair.

His best hope is an operation called a selective dorsal rhizotomy (SDR), which is still relatively rare in this country and not routinely available on the NHS.

It involves loosening the spasticity of the muscles to make it easier for the youngster to walk and run as he continues to grow Mrs Hartin, 39, said: “Time is really of the essence here. The earlier the operation can be done, the greater the chances of its success.

“At the moment, they are not funding the operation routinely and even if you find the money, it can take a very long time to get on the list to have the operation done in England as there are not many places that do it.

“This is why we are looking abroad at Missouri in the US.

“Daniel is such a happy little chap but he is already starting to get frustrated because there are times when he cannot keep up with his sister.

“We want to give him all the help and support he needs but it needs to be done quickly and it will be expensive.

“As well as the surgery, there is all the follow up care and treatment he will need and so we have a lot of fundraising to do.

“It is a pity that we have to take this route but we are trying to be positive about it all. Hopefully our campaign will help educate people about cerebral palsy and we have also had our eyes opened to how generous and supportive people can be.

“The kindness of strangers has been amazing already. We want Daniel to grow up to be an important part of the community.”

The Hartins, who also have another son George, 11, are hoping to book an operation for the end of July or early August, and are aiming to raise more than £60,000 to cover the cost of surgery, travel and follow-up care.

They have raised nearly £9,000 but need to reach at least £30,000 before the operation can go ahead.

Mrs Hartin said: “Daniel has standing equipment to help him interact with his sister and playgroup friends at the same eye level for his development.

“The fact he can’t walk, doesn’t end there. It means his educational and emotional wellbeing is at stake.

“The twins are starting pre-school this September, and it means so much for us to get Daniel on a ‘level footing’ with this sister as far as social interaction is concerned.

“Although the NHS is evaluating the viability of this treatment, I simply want to know what it is they are deliberating on.

“There are thousands of other people, globally, who have had this procedure, children and adults alike, and not one of them that I know about has regretted the decision.

“The choice to me seems simple, if you are a candidate for the surgery, then you will see a positive life-changing outcome. In short you walk, or you don’t.”

One family who know all too well the importance of operations like SDR are the family of five-year-old Oliver Poinsignon.

The youngster, who lives in Steyning with his mother Julie Langmaid, eventually had his SDR surgery at Great Ormond Street Hospital in February following a successful fundraising campaign.

The campaign, backed by The Argus, hit its £52,000 target at the beginning of March, of months of hard work, support and help from family, friends, businesses, charities and individuals across Sussex.

Ms Langmaid and Oliver’s dad, Jean Marc, from Brighton, were another family to find themselves up against red tape when they discovered the operation that could help Oliver, who also has cerebral palsy, was not going to be covered by the NHS.

The youngster is now recovering well from surgery but faces a long process of physiotherapy and support, which also needs to be paid for.

A spokesman for NHS England (Sussex and Surrey), which is responsible for commissioning and approving specialist operations like SDR, said: “We sympathise with families who feel they may benefit from this treatment.

“However selective dorsal rhizotomy (SDR) is not routinely funded by the NHS as the current evidence base does not yet demonstrate sufficient clinical and cost effectiveness for its routine use.

“However, it has been identified by clinicians and patient representatives as showing significant ‘promise’ as a potential treatment option for the future and forms part of the Commissioning through Evaluation programme.

“The commissioning through Evaluation programme, which was originally developed with clinicians treating heart conditions, will enable SDR, and other appropriate services and/or treatments, to be funded within defined parameters, in a small number of participating centres, and within an explicit evaluation programme. Working with patients and lead clinicians, this will give us more information to help determine whether SDR should be made available in the future.”

The issue of funding and red tape has also been highlighted by a mother from East Grinstead, whose seven-year-old child has a rare, muscle-wasting condition.

Benedict McAlister was born with Ullrich congenital muscular dystrophy, for which there is no cure.

His mother Justine and dad Bruce will have to watch as their boy’s muscles continue to weaken over time.

Frustratingly, scientists are in the very early stages of developing a drug that could potentially stop the process of degeneration.

However red tape is likely to slow the research down, which means they are still a long way off from bringing the drug to the clinical trials stage.

The drugs are also likely to be very expensive, sparking more concerns that health bodies may refuse to fund them.

Mrs McAlister said she had been left “frustrated” that plans by NHS England do not highlight how the health service will plan ahead to fund future high-cost treatments for the condition and other rare diseases.

In September last year Justine gave evidence for a parliamentary inquiry on how her family is enduring an agonising wait for a treatment for Ullrich muscular dystrophy.

The findings were published in a hard-hitting report, compiled by the All Party Parliamentary Group (APPG) for Muscular Dystrophy and backed by the Muscular Dystrophy Campaign.

It revealed that while clinical trials are taking place into potential treatments for many forms of muscular dystrophy, families fear that as more cutting-edge therapies for rare conditions emerge, convoluted drug assessment processes, funding issues and lack of specialist care could delay – or even prevent entirely – cutting-edge therapies from reaching children and young people.

MPs involved in the inquiry raised particular concerns over funds after a special budget for treating rare conditions in England was merged into the overall NHS budget in 2013.

Mrs McAlister said: “Benedict is gradually realising that there is something different about him.

“As a parent this is heart-breaking to watch. Scientists are now developing a promising technology that could potentially lead to a treatment for my son’s condition.

“So much hope rests on treatments like this. It’s deeply disappointing and worrying to hear that the NHS England has given no mention to funding for rare disease treatments.

“As more and more pioneering treatments come forward, we and other families are becoming increasingly concerned about whether the system here will be fit to deliver them.

“Urgent action is needed now, so that not a day is lost before these medications reach our children.”

Robert Meadowcroft, chief executive of the Muscular Dystrophy Campaign, said: “We are gravely concerned that failure to plan ahead and lack of funding will delay cutting-edge genetic therapies from reaching children and young people with life-shortening conditions like Ullrich muscular dystrophy.

“Ground-breaking potential genetic therapies are on the horizon and with increased EU support, this pipeline is only set to grow. We need to see funding for treatments and the specialist healthcare needed to deliver them on the NHS’s agenda.”

A spokesman for NHS England said: “Since 1 April 2013, all services included within |The Manual for Prescribed Specialised Services are commissioned directly by NHS England.

“Services provided by adult neurosciences or neurology centres are included in the manual and will be governed by NHS England’s national service specifications.

“However, other non-specialised elements of the care pathway for patients with neuromuscular diseases (NMDs) are commissioned by local clinical commissioning groups (CCGs), in response to the needs of local patients in their communities.

“In the case of this condition, (muscular dystrophy, children may need scoliosis surgery which is NHS England but also lots of physiotherapy which would be commissioned by CCGs.”