In a remarkable domino effect, Daniel Lilburne has repaid a debt to France for stemcells that saved the life of his younger brother Ryan more than five years ago.
The 23-year-old has donated his stemcells so a young French woman could have a bone marrow transplant - the same operation Ryan had in 2008 using stemcells from the umbilical cord of a newborn in France.
Ryan was 15 and battling a serious blood disorder and leukaemia when Perth doctors started scouring an international bone marrow registry for a suitable tissue match to provide stemcells for a transplant.
They initially screened the most likely potential donors - his parents Natalie and Bruce and 17-year-old Daniel - but none matched.
When they failed to find a donor after a worldwide search, doctors decided to go ahead with the second-best option, using stemcells from the umbilical cord of a baby boy in France.
After massive chemotherapy to kill off his diseased bone marrow, Ryan was given the cord blood stemcells and has since made a full recovery, with more than 100 family and friends planning to celebrate his clean bill of health at his 21st birthday party tonight.
But last January, more than four years after Ryan's transplant, Mrs Lilburne was contacted by the registry with news that stunned her.
Daniel had been identified as the best match in the world for a young woman who needed a bone marrow transplant - and she happened to live in France.
"They told me I wouldn't believe - that Daniel was the best match for this girl - and at first I just kept saying 'you're joking' because I couldn't believe the chances of that happening," Mrs Lilburne said.
"If Ryan hadn't been sick, Daniel would never have been on the registry, so I like to think we've helped pay back the generosity of the French family who donated their baby's cord blood."
In August, Daniel donated the stemcells, which required twice-daily injections for four days before and left him with aching bones.
"When I heard about the injections I thought 'hang on, what have I got myself in for' but it wasn't painful and really being able to help a girl in France was pretty awesome," he said.
Just before Christmas, the Lilburnes learnt the 26-year-old woman was out of hospital and doing well.
People aged 18 to 45 in good health can join the Australian Bone Marrow Donor Registry. Details are at abmdr.org.au or contact the Australian Red Cross Blood Service on 13 14 95