Augusto Odone refused to give up on his son

His remarkable survival is due to his parents' single minded refusal to accept the doctors' grim prognosis.

With no scientific training they took on the medical establishment and set about finding a cure. And in 1986 it seemed they had succeeded.

I asked the doctor if I could read the medical papers. He said: 'Don't bother, you won't understand them'.

Augusto Odone

The movie painted a fairytale picture of a miracle cure, and gave hope to thousands of young children suffering the same devastating illness.

But these claims have always been controversial. Now, as BBC television documentary series Medical Mysteries reports, a 10 year study into the effects of Lorenzo's Oil has come up with surprising results.

The oil doesn't seem to work for people who are already ill - but it does seem to prevent illness in those whose genes make them vulnerable to developing symptoms.

Lorenzo suffered from Adrenoleucodystrophy (ALD), a genetic disease that progressively destroys the brain of young boys.

Within a year children are paralysed, blind, unable to speak. It is invariably fatal.

Desperation

When he was diagnosed, Lorenzo's father Augusto was desperate.

"I was terrorised, I was shocked. Well, it's a death sentence.

"So I asked the doctor if I could read the medical papers. He said: 'Don't bother, you won't understand them'."

Both the Stafford brothers had ALD genes

He discovered that the brain damage seemed to be linked to a build up of dangerous fatty acids in the blood - long chain fatty acids.

He invited all the world experts to a conference to discuss the research, and it was at the conference that he first found a glimmer of hope.

An oil - oleic acid - was able to destroy these fatty acids.

Less than a year later Augusto and his wife Michaela had a treatment: a combination of oils that effectively reduced the long chain fatty acids in the blood.

It was astonishing. Where the entire medical profession had failed, two ordinary parents had succeeded.

Optimism

Dr Hugo Moser, the world authority on ALD, remembers that early optimism.

"Lorenzo's oil lowered the fatty acids more effectively than any other medical approach that had been tried. We would be foolish not to give it very serious consideration."

Augusto published his findings and Dr Moser started putting all of his young ALD patients on the oil.

For one family in Britain, news of the Odones' triumph couldn't have come at a better time.

The Stafford family had just discovered that their seven-year-old son Barry had just been diagnosed with ALD.

They flew over to America and Barry became the first British patient to be put on Lorenzo's oil.

Within weeks his long chain fatty acid levels had dropped to normal.

Younger brother at risk

But the Staffords anguish wasn't over. Because ALD is a genetic condition there was a 50:50 chance that Barry's younger brother Glenn would have the defective gene too.

Barry Stafford was the first Briton to use the oil

But a blood test confirmed their worst fears. Glenn too had the faulty gene.

Alfie Stafford, the boy's father, said: "It felt like our world was turned upside down again. We could lose two boys. We could lose two boys within 10 years."

Very little is known about how ALD is inherited. Girls who have the gene do not show any symptoms, and not every boy with the faulty gene goes on to develop the devastating childhood form - ALD.

Glenn might not develop ALD, but Dr Moser put him on Lorenzo's oil in any event.

In fact, Glenn became the first non-symptomatic child to be put on the oil.

Reality different

Over the next few years, the movie Lorenzo's oil, starring Susan Sarandon and Nick Nolte, was released.

It received huge acclaim, and Susan Sarandon was Oscar nominated for her role as Lorenzo's mother.

It showed a miracle cure but the reality was beginning to look very different.

Lorenzo himself was still alive, but was not getting better; and one by one, other children on the oil died.

Barry Stafford was getting worse and worse, and his mother Chris was upset at the hype round the film.

"Lovely film - but I did have a problem - it made it seem like a miracle cure, but it's not and I've proved that with Barry, " she said.

Seven years after being put on the oil, Barry died. The disease had caused massive brain damage and the oil didn't seem to be able to stop the progression.

Barry's fate was not unique. Other children were also dying, despite being on Lorenzo's oil.

Doctors all over the world stopped prescribing the oil.

Preventative effect

It's due to the oil that I'm here now.

Glenn Stafford

Dr Moser, however, was not prepared to give up. He decided to focus on boys who had the ALD gene but had not yet developed the symptoms.

Perhaps the oil could prevent the disease ever appearing. Boys like Barry's younger brother Glenn were put on the oil.

After 10 years the results are finally through. And they are dramatic.

Of 120 boys in the trial 83 are still free of the disease. Lorenzo's Oil is showing a significant preventative effect.

According to Dr Moser taking the oil reduced the chance of getting the disease by half.

And Glenn Stafford, the first non-symptomatic patient to be out on the oil is now 21 years old and fully fit.

"If they hadn't caught the disease and put me on the oil then I don't think I would be here now," he said.

"So it's due to the oil that I'm here now."

So now there is real hope. Tests can identify boys with the gene, and the oil gives them a hugely improved chance of escaping the horrific disease.

And Augusto Odone? He's delighted with the findings. But he's still, 15 years on, looking for a cure for his son who lies at home, paralysed by the ALD.

Medical Mysteries - Lorenzo's Oil was broadcast on BBC One on 21 July at 2235 BST.