Gender disordered children as young as ten are being denied desperately needed hormonal drugs leading to bullying, violence and even suicide according to new research.
Dr Simona Giordano from The University of Manchester says British doctors are depriving children relief from "extreme suffering" caused by their condition - forcing their families into seeking help outside the UK.
The ethicist based at the School of Law contacted US medics who report treating children turned down at UK clinics. Poorer families, however, are unable to afford US medical care she says.
She also suspects that significant numbers of children are suffering alone and without support, though detailed research is needed to reveal the true extent of the problem.
The effect of so called hormone 'blockers' - which suspend puberty- are easily reversible. However other therapies used at later stages - including masculinising and feminising hormones and surgery - are more are more difficult to reverse.
Dr Giordano also discovered controversial guidelines - published in 2005 by the British Society for Paediatric Endocrinology and Diabetes.
The guidelines – which are now withdrawn - laid down that treatment should not start until puberty is complete. But according to the researcher they are still being used.
She said: "Current evidence on risks and benefits of blockers in children and adolescents does not justify the strong resistance of UK specialists, especially considering the risks of refusal of treatment.
"Children are being exposed to the anguish and terror of growing in a body that is experienced as alien.
"It means they will suffer the ill effects of having to begin less reversible treatment on a body which is already fully formed.
"That in turn may lead to more invasive surgery, should he or she decide to transition.
"It' s an intolerable state of affairs: some individuals attempt to buy the hormones from non-medical sources and inject them at unregulated dosages and without medical supervision.
“Some will turn to prostitution to pay for these hormones which exposes them to risks of hepatitis, HIV, and stunted development.
“Many of these people, if they are refused medical help, will do whatever it takes to get hormonal treatment, because they can' t cope with what' s happening to them.
"Lives are certainly at risk and the public is widely uninformed about the matter; even general practitioners often lack competence to identify problems of gender identity and refer children to specialist clinics.
"There’s no data on the extent of this problem at present, though the likelihood is that many young people will be suffering alone and without support. Clinical specialists do seem to be seeing more of these children.”
Dr Giordano also argues that children as well as adults are in some cases competent to give consent to hormonal therapy.
She explained: "There is no legal or ethical ground for presuming that a child or adolescent with gender identity disorder cannot be competent to make an informed judgment about this issue - this disorder is certainly not a mental illness as some medics claim.
“Even if it was, UK law says that a person with a mental illness is not necessarily incompetent to make decisions about treatment for his or her condition.
“We have to presume that these people are competent, unless there is evidence of the contrary.
"If it was impossible to give valid consent to treatment whose side-effects are unclear, it would follow that no-one - including adults - could consent to medical research.
"Each case must be evaluated on an individual basis, without assumption that their consent cannot be valid or that treatment cannot be ethical."