
The 23-month-old, who was being treated at Alder Hey Children's Hospital in Liverpool died at 2.30am, Kate James and Thomas Evans said on Facebook.
The youngster was at the centre of a legal battle over his treatment that touched hearts around the world.
The post on said: "Our baby boy grew his wings tonight at 2:30 am. We are heart broken. Thankyou everyone for all your support."