Joshua O'Halloran, 15, from Portumna, County Galway, had suffered from bilateral hydronephrosis all his life before doctors ordered an emergency transplant.
The disease occurs when urine cannot be drained from the kidneys into the bladder, and patients may need a transplant to lead a normal life.
During the search for a donor, Joshua's father, Francis, came forward as a good candidate and said it would be a “great honour” to donate his kidney to his son.
The surgery took place last week.
“It was an easy decision,” he told Independent.ie.
“It wasn't anything difficult, but just being able to get it done and see him doing well afterwards was such an honor and that's what I really love about it.”
“I knew he needed it and I had the chemistry so I wanted to give it a try. Hopefully, if it works out, great, he won't need another one for a long time.”
He spoke of the difficult 15 years that left his family feeling helpless and searching for their options before their son was admitted to St Mary's Children's Hospital in Crumlin.
Joshua needed to eat a low-protein, low-sodium diet, and his family helped him stick to it.
“That was the most difficult time because we found out he had kidney problems and we had no idea what our path was, how it was going to unfold, what we were supposed to do,” he said.
O'Halloran said he “didn't feel scared” about having the surgery and was happy to have it “for a good cause”.
Joshua was one of 106 children to receive a new kidney at Temple Street Hospital for Children since the first transplant took place in 2003.
Courtney Keeley, now 17, from Slane, County Meath, was the first patient to undergo a transplant at the hospital.
She was born with a dysplastic kidney and was transferred to a hospital where she “grew” while waiting for a donor for six years, she said.
“I'm living a normal life now. I just take medicine in the morning and at night and although I have more machines I don't need tubes anymore,” she said.
“A lot of kids are doing it now.
“I think it's really important that people donate because it will save other people's lives and they will be grateful and their family and friends will be grateful too because it's hard waiting and you don't know how long you have to wait,” she said.
Temple Street Hospital said 70% of transplants carried out at the hospital were performed using organ donor cards.
Dr Michael Riordan, a paediatric nephrologist at Temple Street Hospital, said reaching the 100th case was “a real achievement for the transplant programme”.
“Obviously the most important thing is kidney availability,” he said.
In 2014, 19 kidney transplants were performed, making it the hospital's “busiest year yet.”
“One of the important things that's happening now is that more and more children are receiving kidney transplants and surviving.
“There's been a big advancement in the idea of engaging with kids early in life,” he said.
