A TEENAGER whose medical condition is so rare it has no name is getting ready for a bone marrow transplant which could see him living in a 'bubble' for up to two years.

Ethan Greenwood's only hope to leading an ordinary life is to have his immune system destroyed and replaced with a new one.

The 14-year-old's life-threatening condition is attacking his stomach, pancreas, liver, spleen and both his lungs which are now only working at 30 per cent capacity.

Ethan, who is now at Newcastle's Great North Children's Hospital preparing for his transplant on June 11, started having hospital tests three years ago when he was struggling to eat.

Since then he has been checked for leukaemia, a terminal cancer, Crohn's disease, tuberculosis, HIV and many others but doctors have been unable to find out why his immune system is so damaged.

His mum Sharon Greenwood, 45, said: "All his doctors have been at a total loss. It's so rare what's happening to him that they can't put a name to it."

Ethan was referred from Leeds General Infirmary last year to see consultant immunologist Professor Andrew Cant at Newcastle, one of only two units in the country which perform transplants for immune deficiencies and autoimmune disorders. The other is Great Ormond Street Children's Hospital in London.

"They might never diagnose what he has but Prof Cant hopes the transplant will cure him. They want to completely destroy his old immune system and give him a new one," said Mrs Greenwood who has taken leave for six months from her bank job so she can be with her son, living in specially provided parents' accommodation.

Although Ethan's brothers Connor, 17, and Alex, 11, were a match doctors did not want to use them in case the condition was genetic - an anonymous donor was found instead with help of the Anthony Nolan Trust.

Alex along with Ethan's mum and dad Wayne Greenwood, 46, will be his only visitors allowed on the highly-sterile bubble unit where he will have to stay until the transplant works. He will rely on Skype to stay in touch with his grandparents and friends back home.

"Usually it's babies and toddlers they treat on the bubble unit, Ethan will be the oldest one. He's had one bout of chemotherapy which is part of getting ready for the transplant and he's been at home under house arrest. He hasn't been able to go out unless he's been wearing a mask," said Mrs Greenwood.

Ethan, a pupil at Guiseley High School, is having a central line fitted into his chest in readiness for going into the Bubble - an 8ft air-locked room with its own oxygen supply - in the run up to his transplant day.

His special room will have its own nurse's station, a private bathroom and TV - the work of the unit is supported by a fundraising campaign called The Bubble Foundation UK at bubblefoundation.org.uk.

Mrs Greenwood, of Fieldhead Drive, Guiseley, said: "The transplants have an 80 per cent success rate.

"If everything goes well he should be completely cured. It could take months, the shortest transplant time at the unit has been eight weeks but it could take up to two years."

Prof Cant said: "We know what's wrong with him, he has complex auto-immunity but we don't know why.

"His immune system isn't controlling itself. It's like having an army that roars into action but won't be demobilised and go back to civvy life after the battle.

"His system is constantly overactive. It's like living in a garrison town where the soldiers go down the pubs and smash them up."

"Ethan is a brave lad, very sensible and he knows he needs this transplant even though it's not without risk. We are doing frontier of science stuff here and have made some fantastic discoveries but they don't explain Ethan's case . One day we will nail why this is happening to him, not yet but we will."