At every turn, the doctors and nurses charged with the child's care encouraged the parents to end the kid's suffering. The parents were absolutely invested in using all of their resources to give the child "the best care". The last few years of the kid's life were basically vegetative, with frequent interruptions of how a human with an obliterated nervous system manifests pain.
I'm sorry if this reads all tragic and horrible, but that's what it is. There should be laws preventing family members from prolonging the suffering of their loved ones.