Little Billy Twitchen is the picture of joy as he plays happily with his toys and runs around with his school friends.
It has been a long journey for the brave youngster, who has survived life-threatening liver disease, an organ transplant and cancer caused by his medication – all by age three.
Terrified parents Laura and Alec feared they would never get to see their son reach normal milestones, such as celebrating birthdays or going to school.