An increasing number of children in the UK are turning to support services for transgender treatment, as they battle with the distressing feeling of being born the wrong sex.
The number of children aged 10 and under referred to The Tavistock and Portman NHS Trust has more than quadrupled over the past six years.
Of the children refereed, 47 were aged five or younger and two children were just three years old, according to the BBC's The Victoria Derbyshire programme.
Two of the UK’s youngest transgender children recently spoke to the programme with the permission of their parents and the support of their schools.
Friends Lily and Jessica (not their real names) who are aged six and eight were both born boys.
Form an early age the pair were very aware of their gender and they were both uncomfortable and even distressed about being boys.
"When did I decide I was definitely a girl? Well my whole life really," Lily told Victoria Derbyshire.
She noted she would be really upset if she had to live as a boy and was feeling much better since she started living as a girl.
Jessica added that she found being a boy really frustrating and felt that she did not "fit in".
Lily and Jessica both have a medical condition known as gender dysphoria or gender variance.
A survey of 10,000 people by the Equality and Human Rights Commission in 2012 suggested that one per cent of the population was transgender. However this statistic may not be accurate as many people do not seek help.
The NHS Trust says that gender dysphoria in young people is a "complex and rare condition where there is incongruence between the young person's perceived gender and their biological sex".
While many people may question how children so young can be sure they identified as the opposite sex, Ms Derbyshire reported that Lily and Jessica both seemed adamant about their decision.
Lily’s mother Jen admitted that coming to terms with the fact that your child is transgender is very hard.
“We watched a video two years ago. It was an American video of families talking about having transgender children and I thought , 'my gosh, this is what we're facing',” said said.
She noted there was not a specific moment when her husband and herself realised Lily was experiencing gender dysphoria, as it was something that happened gradually.
The NHS Trust says it does not consider it helpful to make a formal diagnosis in very young children, according to the programme.
Instead they monitor them over time and facilitate counseling and support sessions. Medical intervention is not considered until a child approaches puberty, when hormone blockers might be offered.
Experts say gender identity issues can be traumatic for a child and their family, particularly when the child reaches puberty.
Recent research published by mental health charity PACE shows that 59 per cent of transgender young people said they'd self-harmed, compared with just under nine per cent of all 16-24 year olds.
This is something Lily and Jessica’s parents hope they will be able to protect their girls from and it was the reason why they and the girls were happy to talk to the programme about their situation.
Morning news break – April 6