Changing sex: can a child decide?

When a child is born a boy, but grows up feeling that he is actually a girl, or vice versa, it is known as gender dysphoria.

In Britain, doctors are reviewing guidelines for the treatment of young people with the condition.

A key issue is the age at which they can be prescribed drugs to pause puberty.

In the UK it is currently around 16 years old, but some other countries allow it at around 12.

So, what issues do young transgender people face?

And when should they be able to begin changing their bodies?

The BBC's James Fletcher has been talking to a mother and daughter (their names have been changed to protect their identities).

Dr Norman Spack is a paediatric endocrinologist from the Children's Hospital, Boston.

He treated the teenager James heard from.

How does he answer those who say gender reassignment is wrong?

First broadcast 30 October 2009