The family of a young man who died suddenly are running the Belfast Marathon to raise money for research into undiagnosed heart conditions.
Joe Burns passed away in July 2014 after collapsing at his parents' home.
The 23-year-old from north Belfast, who was a popular barman at The Chester, was a fit and healthy boxer who trained regularly in the gym.
A day after his death his girlfriend Sinead discovered she was pregnant with their daughter Bella, who is now two.
The young man's family spent months not knowing how Joe had died.
They were referred to the inherited heart conditions clinic in Belfast for genetic testing.
They have since learned that Joe's mum Una and sister Jeanette both carry the faulty gene for Long QT - an inherited condition that can cause heart rhythm disturbances. Left undiagnosed, it can cause sudden death.
Ten members of the family and their friends are running the marathon on Monday to raise funds for British Heart Foundation.
Joe's dad, also called Joe, said: "After Joe died we didn't know what had caused it.
"His heart was sent away for tests and even now these tests are still ongoing. Our family was referred to the Royal Hospital for cascade genetic testing. We had amazing support from BHF nurse Tracy Jardine, who was just fantastic. She was always on hand to answer questions and help us through the tests.
"On top of the grief of Joe's death we had the worry that we might have an inherited heart condition.
"We've since discovered that my wife Una and daughter Jeanette carry the faulty gene for Long QT. We might not ever know that's what Joe died from, but it looks likely that's what it was.
"Joe was always giving back and we want to give back too. That's why this year we are running the Belfast Marathon in his memory for BHF. Firstly, because of the support we had from Tracy, and also to fund research into Long QT and other heart conditions that take the lives of young people like our son."
Every month in Northern Ireland at least one young person dies from an undiagnosed heart condition. British Heart Foundation Northern Ireland (BHF NI) estimates that around 17,500 people here are living with a faulty gene that puts them at high risk of a heart attack at a young age or sudden death.
Joe added: "We have been training hard for the marathon and are delighted that 10 of us are taking part in relay teams, and there are two more doing the full race.
"We don't want other families to suffer like we have, so knowing the money we are raising will go into research into heart conditions that take our young people is brilliant.
"We want to thank all our family and friends for their support and we're looking forward to crossing that finish line."
Karen McCammon, who is a specialist heart nurse in BHF NI, said: "We want to thank the Burns family and all their family and friends for their generosity.
"One young person here dies every month from a heart condition they didn't know they had.
"That's every single month another family is facing the shock and devastation of losing their son, daughter, husband or wife.
"It tears people like Joe away from their families when he had so much to live for."