DUBLIN - A video of a girl with autism singing Leonard Cohen's Hallelujah has gone viral due to the 10-year-old's stunning vocals.

Kaylee Rodgers, who has autism and attention deficit hyperactivity disorder, sang the song at her school's Christmas show.

She is a student at Killard House Special School in Northern Ireland and is often shy, says headteacher Colin Millar - except when she sings.

"When she sings, she just opens up," he told the media in Britain. "To stand and perform in front of an audience is amazing. It takes a lot of effort on Kaylee's part."

According to Britain's National Autistic Society, the characteristics of autism - a developmental disability - vary from one person to another, but usually include persistent difficulty with social communication and social interaction.

A video of the school choir's version of Hallelujah has gained over 900,000 views after being posted on Facebook on Dec 19.

"Absolutely stunning. If this doesn't inspire you, I don't think anything will," commented one Facebook user.

"Beautiful voice and the choir were brilliant," another Facebook user commented. "Hats off to special needs teachers all over who produce these concerts that leave all of us in tears of pride and joy and sometimes laughter."

Kaylee started attending Killard House a few years ago, in order to help her address learning delays.

Millar says the school has helped Kaylee, and other students, discover their special abilities.

"All my kids have talents, as well as barriers, and this is hers," he said.

Kaylee spoke with Britain's ITV about her joy in singing the song.

"It was really amazing how many views I got... I just loved doing it."