Adele Markham, 31, describes herself as a 'normal girl' who loves clothes and one day hopes to be married.
But for 28 years Adele was known as Matthew and was living as a man until a stunning medical discovery revealed her true sexual identity.
For Adele was born with an extra sexual gene and though technically male - and growing up as a 'boy' - she always had doubts about who she really was.
When 'Matthew' was born, Adele's parents were delighted to be told they had a son as they already had two daughters.
But as Matthew started to grow into a toddler, the family GP noticed problems with his genitals.
'The doctor told my parents that I wasn't developing normally,' said Adele.
'The doctor told my mum and dad I would need an operation when I was older. But they didn't know what had caused the defect.'
As a small boy, Adele sounded and acted effeminate, and loved playing with other girls. But she was constantly punished by her family for being 'too girly'.
People with Klinefelter's syndrome are born with an extra sexual gene, so while boys are usually XY and girls are XX, Adele's genes are XXY.
Although most boys with Klinefelter's syndrome grow up to live as men, some do develop female gender identities like Adele.
But chromosome tests were not carried out at the time and no-one suspected anything was different about Matthew.
'I always felt like a girl,' said Adele.
'But my parents didn't want to hear it. They had no reason to think I wasn't a boy. My dad was quite old fashioned and he expected me to act like a rowdy boy and play football. But I'd rather play with dolls like my sisters.
'At school I always used to hang around with girls. I hated PE or anything where I had to be in a male environment.
'I was very close to my sisters and used to steal their clothes and dress up in them, which made my dad really angry when he found out.'
By the time Adele reached 14 she had still not been through male puberty and her worried parents took her to see a specialist to ask how they could make her more masculine.
They were told testosterone would help her grow and develop into a man.
So on the doctor's advice, and following her parent's orders, she began taking male hormones in tablet form every day. But Adele says even though she was terrified of turning into a man, the treatment actually backfired.
After a few months, Adele began to go through puberty. But as is common with people with Klinefelter's syndrome, she didn't develop a deeper voice or grow facial hair and actually developed small breasts.
'I never had a male puberty, so that just reinforced this feeling inside that I was meant to be female,' she said.
Later that year Adele was taken into care, after confiding in a counsellor about her feelings and receiving no support at home. She was also referred to a gender clinic as it was thought she might have symptoms of being transgender.
She said: 'I kept having medical problems with infections. But no-one ever ran a genetic test to see if there was something else behind it all.'
Not realising she had a genetic disorder, Adele blamed herself and felt confused and alone.
So at 16, she shaved her head and ran away to London, where she joined the gay scene as a young man.
She said: 'I was very confused. I didn't really feel like I belonged to the gay scene. But I knew I was attracted to men.
'But I decided that I would try to live as a gay man. It seemed to be easier.'
Adele Markham aged 18 (left) and nine (right) when she was called Matthew. She was only diagnosed with Klinefelter's syndrome when she was 28.
Adele spent hours at the gym bulking up her delicate frame, and had large masculine tattoos etched onto each arm.
After almost a decade of living a lie, Adele, aged 28, finally plucked up the courage to see a doctor and explain how she felt.
'He was great,' she said.
'He explained to me that there had been big changes in understanding how people's gender worked in the last few years.
'The doctor got me to do a series of tests to see if I was suitable for a sex change.'
Adele was called back a week later to get the results and was shocked by the news.
'The doctor explained I had something called Klinefelter's syndrome, which meant that I wasn't really male, or female, but 'Intersex" - a mix of both.
'I was shocked. My whole life I'd been told that the way I felt was wrong, and was something to feel ashamed of, but in a few minutes he explained to me that it was okay to feel that way, because it was true.
'I felt excited, terrified, emotional, all at once.'
Adele started taking oestrogen and is set to have an operation to complete her transformation.
Adele decided to turn her attention to London's young people and now runs a project called "Silverfish" for homeless and drug-addicted intersex people.
'I'm just a normal girl who wants to settle down and get married one day,' she added.
'I battled for over 20 years to be a female, and now I finally know who I am.