The family of two boys needing vital kidney transplants have been told one of them will have to be saved first.
Luke and Ashley Campbell share a genetic condition
Luke and Ashley Campbell, two of a set of triplets, suffer from the same rare kidney disease.
They have been waiting for 17 months for suitable organs to become available.
Their parents, from Newport, south Wales, had planned for them to have the operation at the same time but have been told that is not possible.
The decision has been taken out of the hands of Melanie and Steven Campbell, and a hospital consultant will now decide which of their 13-year-old sons will receive the operation first.
"It is going to be hard for the one who has to wait and it will be an agonising time for us," said Mrs Campbell.
"We will be praying it won't be long before he is also given a transplant," she added.
The couple have known for nine years that both Luke and Ashley would need transplants one day.
The two boys have been diagnosed with the hereditary condition familial juvenile nephrophthisis.
Both Mr and Mrs Campbell carry the gene which only affects boys. Their daughter Sinead is perfectly healthy, as is their other son, 15-year-old Gavin.
The condition causes gradual loss of kidney function due to cysts.
Mrs Campbell, 35, said she can still remember being told about the boys' condition.
"I was absolutely devastated, I can remember going into a room and I just wanted to punch somebody," she said.
"I felt so angry. Steven and I both carry the gene but we did not know it.
"We'd never even heard of this thing before - but it has had a huge effect on our lives.
"Luke and Ashley have been very brave - they don't complain but they are going through it.
"They are very close and which ever one goes first for the transplant - the other will be supporting him all the way," she added.
The family have managed to come to terms with years of constant medication, hospital visits and tests.
The boys have regular dialysis sessions lasting eight hours and the dialysis machines are even taken on holiday with them.
Mrs Campbell has to carry a bleeper in case a kidney becomes available for one of her sons, who both attend Bassaleg Comprehensive in Newport.
The teenagers were told they would need transplants last year but they have waited longer than average because of their rare tissue.
In the meantime, Mrs Campbell is raising money for the National Kidney Research Fund.
She is also supporting a campaign to change the organ transplant system in Britain from the current donor card one to an "opt-out" system, where people would have to actively choose not to become donors.