Where little girls turn into boys at puberty!

While bodily changes at the time of puberty such as voice cracking and mood swings are all too common among boys worldwide, the transformation that some undergo at a remote village in the Dominican Republic is extraordinary - these boys grow a penis only when they hit puberty.

The story of these children who live in Salinas, an isolated village in the southwestern Dominican Republic, features in a new BBC science series "Countdown to Life - the extraordinary making of you".

One in 90 children in Salinas face this rare genetic disorder, telegraph.co.uk reported.

In their village, these children are simply referred to as the 'guevedoces' - which literally translates as 'penis at 12'.

The 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, the report said.

Because of this missing enzyme they appear to be born female with no testes and what appears to be a vagina.

The male reproductive organs emerge during puberty at around 12 years of age due to a huge surge in testosterone.

So what should have happened in the womb happens around 12 years later.

Their voices deepen and they finally grow a penis.