This is more about the rights of the state to control medical care, than the right of a child to live.
In truth no matter what the parents had chosen, if it is not the position of the state, it would be wrong. This would not normally be a moral conundrum, for we assume that there are certain rules made to protect the lives of children. But that is not the case any more; many parents who wish their ill babies to receive the best of care are being told that their babies must die because of "quality of life issues". So it is not about protecting the life of this child, it is about state control over health care.
Had this young man's parent's wished him to live in spite of chronic disability or condition, the state might decide that it would be "in the child's best interest" to take away "life support" or medical treatment that constitutes "heroic measures". Likewise, if the subject were a pregnant teenage girl, the parents would be told that they have no right to know or influence the child away from an abortion. So the moral conundrum in this case is nullified - this young man is not taking the official state mandated health care regarding his choices for his own life, so alternatives are forbidden.
This is about state control of health care, and about the will of parents and patients being ignored.
Well said.