Is 'best interests' the right standard in cases like that of Charlie Gard?

Savulescu and colleagues have provided interesting insights into how the UK public view the 'best interests' of children like Charlie Gard. But is best interests the right standard for evaluating these types of cases? In the USA, both clinical decisions and legal judgments tend to follow the 'harm principle', which holds that parental choices for their children should prevail unless their decisions subject the child to avoidable harm. The case of Charlie Gard, and others like it, show how the USA and the UK have strikingly different approaches for making decisions about the treatment of severely disabled children.