Agree with you Sophocles about parental rights framing not being helpful. A parent could agree with this course of action and that would still harm the child.
The principle for parents must be preserving the child’s natural physical integrity for future choices, not closing them off while they are still children. All children have a right to to an open future.
Health services should be providing abundant psychological support and years of watchful waiting before any physical intervention. Names, clothing whatever all absolutely fine to present socially as the child wishes but always explicitly holding on to the reality that sex can’t actually be changed.
No permanent-impacting treatments unevidenced for safety or effectiveness should be given and especially not when they already have very serious known side effects on mental health, bone density, IQ, cancer risk.
And when they are NOT reversible but have been sold that way, that is unforgivable. A double mastectomy could permanently remove nerve endings providing skin sensation including sexual pleasure and also future breastfeeding potential in one fell swoop.
Yes with further pain and risk and expense some women can potentially have breast reconstruction but by definition it’s not the same as a natural breast. I’m not even mentioning the psychological impact of repeated invasive surgeries on secondary sexual characteristics. I hope I’m not offending anyone by saying any of that, I am very concerned at how society already minimises and consumerises breast surgery as ‘boob jobs’, while sexualising children‘s and young people’s bodies, meaning that many dysphoric young people will have been groomed into a heavily misogynised mindset around theIr own bodies. Full adult maturity, for making decisions of this gravity is also in my view not gained on anyone’s 18th birthday.