A father who gave up his job three years ago to find a cure for the world's first genetic disease - which affects both his sons - has discovered a treatment for it.

Nick Sireau, 40, discovered his sons Julien and Daniel had alkaptonuria, known as black bone disease, when they were babies. The disease affects just 60 people in the UK.

Mr Sireau left his job as a charity boss in 2010 in order to research potential cures with medical specialists, and they consequently discovered that the drug nitisinone was a "very, very effective treatment."

He told BBC Radio 5 live's Victoria Derbyshire: "They said there is no treatment and we should basically go home and try not to think about it... but we went home and thought 'we need to do something about this.'"