They call them the "machihembras" — the men who are born as women.
The group, who live in Salinas, an isolated village in the south-western Dominican Republic, suffer from a genetic deformity that has stunned scientists. Despite appearing to be girls at birth, they are biologically male and only when they approach puberty do they develop male organs.
Johnny is one of the many children affected. While his story may seem extraordinary, cases of little girls turning into boys are so prevalent in the village of Salinas that it is no longer considered abnormal.
Johnny, 24, was originally named Felecitia by his parents and brought up as a girl.
"I remember I used to wear a little red dress," he said. "I was born at home instead of in a hospital. They didn't know what sex I was. I went to school and I used to wear my skirt. I never liked to dress as a girl. When they bought me girls toys I never bothered playing with them. All I wanted to do was play with the boys."
His story will be featured in a new series Countdown To Life — The Extraordinary Making Of You by British broadcaster BBC 2. The rare genetic disorder occurs because of a missing enzyme, which prevents the production of a specific form of the male sex hormone — dihydro-testosterone — in the womb.
All babies in the womb, whether male or female, have internal glands known as gonads and a small bump between their legs called a tubercle. At around eight weeks, male babies who carry the Y chromosome start to produce dihydro-testosterone in large amounts, which turns the tubercle into a penis.
But some male babies are missing the enzyme which triggers the hormone surge, so they appear to be born female.
It is not until puberty, when another large surge of testosterone is produced, that the male reproductive organs emerge and their voices deepen.
What should have happened in the womb, happens around 12 years later.
For Johnny, it happened at the age of seven. He claimed that he had never felt like a little girl and was far happier after he fully became a boy.
"When I changed I was happy with my life," he said.
A little boy named Carla is currently going through the same transformation, aged nine.
Despite being brought up as a girl, his mother noticed that from the age of five he was more inclined towards the rough and tumble play of boys. He has recently had his hair cut short after wearing plaits.
Many decide not to change from their female names, so some men in Salinas have names such as Katherine.
Also referred to as the Guevedoces — which translates to "penis at 12" — they were first discovered by Dr Julianne Imperato, an endocrinologist at Cornell University in the 1970s. Further cases have since been seen in the Sambian villages of Papua New Guinea, although the Sambians often shun the children, unlike the Dominicans, who celebrate the change.
Approximately one in 90 children in Salinas are affected and although they resemble sexually normal males, subtle differences do still exist in adulthood. Most have decreased amounts of facial hair and smaller prostate glands relative to the average male.
It is thought that the condition has persisted through generations because of the isolation of the villagers.