RE: School Email Today2 Mar 2021 14:30
The tests are classed a classed as clinical procedures and therefore require consent.
That said, even if the parent refuses to consent, there's nothing to stop the child (anyone under the age of 18 in these circumstances) consenting in their own right, as long as those administering the test are satisfied they understand what they are consenting to (the Gillick Competence test).
I'm willing to place money I could guess what sort of parents are withholding consent...