Jake Parkin from Sheffield was diagnosed with juvenile chronic myeloid leukaemia, a rare form of leukaemia, which did not respond to chemotherapy.

Doctors did not think he had time to wait for a bone marrow transplant - the usual treatment in such cases - so instead he was given an umbilical cord transplant from an American newborn baby.

The blood, which was squeezed out of the afterbirth, contains a high concentration of the stem cells necessary to promote new growth of blood cells and boost the immune system.

Stem cells are also an important component of bone marrow transplants.

Frozen blood

The blood from the Missouri baby was found to be a 95% match for Jake. It was frozen and flown over in a special sub-zero container.

It was then thawed at Sheffield Children's Hospital and grafted to Jake in a groundbreaking operation.

To avoid infection, Jake had to stay in isolation until his blood count reached an acceptable level.

Doctors say there are early signs that the transplant has taken and Jake has been allowed home, although he has to go to the hospital for check-ups.

His mother Cheryl said: "We have trouble holding Jake down now.

"He thinks his hospital bed is a trampoline and he was desperate to get out of isolation and onto the ward to play with some new toys. It is so lovely to see him getting back to his old self."

Charity

Worldwide only around 100 cord blood transplants have been carried out from an unrelated donor.

There have been three cord blood transplants in the UK. The first two were from sibling babies.

Jake's parents have agreed to publicise his case to highlight the work of Sheffield charity PACT (The Parents' Association of Children with Tumours and Leukaemia).

The charity provides facilities, such as kitchen and phone, for parents while their children are in hospital. They also put up families who come from outside the area.

The Leukaemia Research Fund said Jake's operation was "very exciting".

It is carrying out major research into cord blood transplants.

Great hopes

"We have great hopes for this operation," said a spokesman, adding that the match between patient and donor does not have to be so tight in cord blood transplants as in bone marrow transplants

The blood from the afterbirth is high in stem cells

He said there were areas that needed improvement. No adult with leukaemia has ever had the operation in the UK, for example.

This is because it is believed more stem cells are needed than can be found in one cord blood sample.

Research is going on into whether cells can be grown artificially or samples can be mixed together.

Three cord blood banks are up and running in the UK and others are in the pipeline.