I would love to have my son back, says mother of five-year-old boy who lives ... - Telegraph.co.uk

"We leave it up to him to decide what he wants to do. If he changes his mind and wants to be a boy again then he does, but if he doesn't, he doesn't.

"People need to be aware of this condition because it's very common but even many family support workers have never heard of cases in children."

She said Zach had been a "normal" little boy who loved Thomas the Tank Engine. But towards the end of 2010, he became obsessed with the children's television character Dora the Explorer and started dressing in girls' clothes.

Mrs Avery said: "He just turned round to me one day when he was three and said: 'Mummy, I'm a girl'. I assumed he was just going through a phase and just left it at that. But then it got serious and he would become upset if anyone referred to him as a boy."

She said Zach, who has three siblings, used to cry and tried to cut off his penis out of frustration. Mrs Avery and her husband Darren, 41, took their son to a specialist at the Tavistock and Portman NHS Foundation Trust in London and after several months of consultations and observations, a child psychologist diagnosed gender identity disorder.

Now Zach is almost unrecognisable. With his long hair tied back in pigtails, pink glasses and a collection of dolls, his parents have acknowledged that Zachy, as he is now known, is happier than he ever was.

They said the local primary school in Purfleet, Essex, had been "really supportive" and that pupils had been told that Zach, who wears a girl's trouser uniform, was simply happier being female. The school has even converted some lavatories to gender-neutral unisex.

"We explained to the other kids at the school that Zachy's body was that of a boy but in his brain he was a girl. We said Zach was just happier being a girl than a boy," said Mrs Avery.

"But the other kids haven't batted an eyelid, they've accepted Zach as Zach and there's been no problems at the school with bullying.

"The school has been brilliant and really, really supportive."

Earlier this year a couple from Cambridgeshire attracted widespread attention when they announced that they had raised their child as "gender neutral" for five years so the infant's "real personality" could shine through.

Beck Laxton, 46, and her partner Kieran Cooper, 44, from Sawston, decided not to disclose baby Sasha's gender to the world so he would not be influenced by society's prejudices and preconceptions.

The Tavistock and Portman NHS Foundation Trust, the national body for gender identity disorder, said the number of children diagnosed with the condition had steadily risen from 97 in 2009-10 to 165 so far this academic year, which it said may reflect greater awareness. Only seven children under the age of five were diagnosed last year.

A spokesman said the groups's aim was "to support the young person in their general development as well as develop a trusting collaborative therapeutic relationship in which it is possible to openly explore their feelings about their gender. We remain in contact with young people often for many years".