In every way, Johnny is physically and biologically male. But, astonishingly he did not grow a penis until he hit puberty.

He is one of many children who live in Salinas, an isolated village in the southwestern Dominican Republic, who are seemingly born female, only to become men in their teenage years.

Although Johnny’s story may seem extraordinary, cases of little girls turning into boys are so prevalent in the village that it is no longer considered abnormal. The children are simply referred to as the ‘guevedoces’ – which literally translates as ‘penis at 12’

Johnny, 24, was originally named Felecitia by his parents and brought up as a girl. He spoke to Dr Michael Mosley for the new BBC2 series “Countdown to Life – the extraordinary making of you"

“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.”