A High Court judge has ruled that doctors can provide only palliative care to a "profoundly neurologically disabled" two-year-old boy.
NHS hospital bosses with responsibility for the boy's care had asked Mrs Justice Parker to rule that limiting treatment to palliative care would be lawful and in his best interests.
Specialists said the little boy suffered from an incurable but unidentified neurological disorder - and that his condition was deteriorating.
Nurses said he had stopped smiling and that he grimaced but no longer giggled when tickled.
Specialists said ''further invasive interventions'' would be distressing and burdensome for the little boy and would have little or no therapeutic benefit.
The youngster's parents disagreed with the idea of providing only palliative care and implementing an "end-of-life plan".
They said all treatment options should continue to be available.
Mrs Justice Parker had overseen the case at a public hearing in the Family Division of the High Court in London and made a ruling on Wednesday.
She said it was not in the little boy's best interests to "artificially prolong" his life.