With a love of bikes and go-carts, Joe Cawse looks just like any other seven-year-old.

However, one devastating fact makes him very different indeed.

Joe is one of only a handful of children in the UK to suffer from an extremely rare form of leukaemia.

The youngster was just four when he was diagnosed with juvenile myelomonocytic leukaemia (JMML), a disease which can only be cured by a bone marrow transplant.

He is one of only about 10 children with the disease in the UK.

Without a transplant, 94 per cent of suffers, most of whom are under five, die within two years of diagnosis.

But despite the fact that about 12 million people worldwide are on a bone marrow register, no match has been found for Joe.

His mother, Sheridan, of Abbots Field, Barming, said: “We discovered he had a very rare tissue type.

“Both his brothers, Dan, 13, and Ben, four, were tested and they are a match for each other but not for Joe.

“He is one unique little boy.”

Joe’s unusual make-up has presented his family with one blessing: he is among only six per cent of JMML suffers who do not automatically need treatment.

For the time being he can continue to live a normal life and only needs to go for six-monthly check-ups at hospital.

Mrs Cawse said: “He gets covered in bruises and if he is ill it lasts longer than normal, but basically he leads a regular life.”

But the situation could deteriorate at any time, and without a suitable donor Joe’s life would be critically under threat.

His mother said: “It is like living with a time bomb.

“When Joe was first diagnosed we felt our world crash in on us.

“Fortunately he has not deteriorated but we are still anxious that a suitable donor may not come forward.

“Knowing someone was there if he did get sick would take away all the worry of the past three years. We are living on a knife edge.”

Joe, a pupil at West Borough Primary School, will celebrate his eighth birthday on Saturday.

Joe's mother is urging people to put themselves on the bone marrow donor register in the hsope that a match can be found for her son..

An Anthony Nolan Trust clinic takes place on Wednesday, July 9 between 3.30pm and 7.30pm at St Francis Catholic Primary School in Queens Road, Maidstone.

Mrs Cawse said: “I just want people to understand how vital it is to become a donor. You could have the capability to cure one of the nastiest diseases we know about.

“People who come along really could be life savers.

“We are not expecting to find a match for Joe, but thousands of other people need help too.

“When it is your own child you do become desperate. There has got to be one person out there who matches him and who knows, they could show up on Wednesday.”

About 70 per cent of patients who need a transplant do not have a suitable sibling match so an unrelated donor to offer them the chance of life.

Every year in the UK 27,000 adults and children are diagnosed with leukaemia.

For many of them a bone marrow transplant offers the only possible long-term cure.