A video telling the story of a transgender six-year-old in America has had more than four million hits on YouTube.

In the seven-minute film, a younger Ryland Whittington is seen saying, "This is my sister Brynly and I'm her brother, Ryland."

His family, who posted the video online, say Ryland was born a girl but is now being raised as a boy.

"As soon as Ryland could speak she'd scream, 'I am a boy'," they said.

My name is Ryland Michael Whittington. I'm a transgender kid. I am six. I am a cool kid Ryland Whittington

"She said, 'When the family dies, I will cut my hair so I can be a boy'."

After speaking to professionals, the family decided Ryland's experience was more than a tomboy phase.

They decided to change Ryland's identity, cutting his hair, changing his clothes and referring to him as "he".

"We all came to the same conclusion... Ryland is transgender," they said.

His parents, Jeff and Hillary, sent a letter to their family and friends about the change.

"We lost a few... but the people who truly matter stuck by us," they admitted.

Californian gender therapist Darlene Tando told ABC News in America: "There are huge benefits of doing this earlier in life. It's really just like they have been given this gift that everyone around them starts seeing them for who they are.

"With phases they just come and go but with gender identity, when a child is transgender, typically nothing fades in or out."

The video also shows Ryland speaking at a recent equality event in California, where he thanks his parents and says he's a boy.

"My name is Ryland Michael Whittington," he said. "I'm a transgender kid. I am six. I am a cool kid.

"I am the happiest I have ever been in my whole life."

In the UK, the Gender Identity Research & Education Society claims that a school of 1,000 pupils should expect around 10 children to be gender variant to some degree.

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