Adam Kirk, who is 10, was born with PK13 kinase delta deficiency meaning he is unable to fight off infection.
The youngster underwent a bone marrow transplant four years ago, but doctors only recently told his family that it wasn’t successful.
Now he must endure two weeks of painful chemotherapy to destroy his existing bone marrow, before having a second transplant.
Adam’s mother, Louise, said: “We were hoping the transplant he had in June 2013 would build a brand new immune system to fight off its own infections so he could lead a normal life. He seemed to be doing okay for the first three years but we recently found it had not worked and the chest infections have returned in the last six months.
“We’re looking at a second transplant from the same donor in America who matches Adam, this time to either give him more or try a new procedure to replace his stem cells.”
The Castleford Park Junior School pupil often has to be taken out of school during outbreaks of any contagious illness, including common colds.
Despite being rare, Adam inherited the condition - sometimes known as Severe Combined Immunodeficiency (SCID) - from Louise who had been told it could not be passed on.
Louise, like Adam, has to undergo regular injections of anti-bodies to fight infection.
“When he was born, he had the same symptoms as me, recurring chest infections,” she said.
“The GP kept telling me he was normal, but when he was four I took him to see my specialist and was told we had the same condition. I was gutted, but I knew all along.”
Louise is now organising a family fun day on September 30 at Castleford Panthers’ ground on Raglan Close to raise awareness of the condition and money for The Bubble Foundation, a charity which helps babies born with defective immune systems.
Held from 2pm to 8pm, there will be a bouncy castle, face painting, a bungee run and a magician.