Just four months ago Sam was diagnosed with a rare condition which is slowly destroying his muscles, and sadly will eventually cut his young life short.

The condition is Duchenne Muscular Dystrophy (DMD), and it is so unusual that even Sam's mother Emma, a paediatric nurse at Addenbrooke's Hospital, hadn't heard of it.

But now Emma, 30, and her husband Daniel, 33, are speaking out about Sam's condition and the devastation it has caused their family in a bid to raise both awareness and money for the Action Duchenne charity.

The couple have lived in The Paddocks, Somersham, for more than eight years, now with Sam and five-year-old daughter Amy.

But on March 5 this year the family's lives changed forever.

In the six months leading up to the diagnosis Sam's parents noticed he had been falling over a lot and was behind with his speech.

Emma said: "We put everything together and spoke to some doctors. Sam had some blood tests and the one which tests for DMD was really high.

"It was devastating and we were in utter disbelief. I didn't know anything about it, so I just wanted people to be aware."

One of the symptoms of DMD is large calf muscles, but apart from that there is often no way of diagnosing the problem until the child starts walking and talking.

Often a hereditary condition which affects mostly boys, DMD can be passed on through the mother, or it can just occur for no apparent reason. Emma is still waiting to take a genetic test for the condition.

Emma added: "It's one of the most severe muscle-wasting conditions there is. As a rule sufferers tend to be in a wheelchair by the age of ten, by their teens they are more or less paralysed and they don't live much past their early 20s.

"Just by looking at him you can't really tell. He's just so happy and he is the cheekiest little chap ever. We just can't comprehend it at the moment."

Although there is currently no cure for DMD, Sam has already visited Great Ormond Street Hospital and started receiving physiotherapy treatment. He will soon wear night splints to help keep his feet in position.

Sam already attends Parkhall Playgroup in the village and is set to start Somersham Primary School next year, but by the age of four he will be taking steroids to help his condition.

However, the Jerred family are not alone, and have help from national charity Action Duchenne, which lobbied the Government a few weeks ago in a bid to raise £2 million to fund new research and clinical trials.

And now Emma's school friend of 20 years, Karen Roberts, from Bedford, is running 50 miles, in seven races, to raise much needed cash for the charity.

>> Karen will be running 10km (6.2 miles) through St Ives on Saturday, July 20. To sponsor her visit www.justgiving.com/karenroberts1