Families starring in a "carpool karaoke" video featuring children with Down Syndrome say they are overjoyed by the worldwide reaction.
The clip features 50 youngsters and their mothers singing along and using Makaton sign language to the Christina Perri hit A Thousand Years - all done in the style of James Corden's carpool karaoke section of The Late Late Show.
It has now been viewed more than a million times on YouTube and Corden himself described it on Twitter as "the most beautiful Carpool Karaoke".
Perri also used Twitter to say: "THIS IS THE BEST!!!! I'm so honored they chose my song! my heart is so full!!!"
Both stars used the hashtag #wouldntchangeathing promoted by the 50 Mums, 50 Kids, 1 Extra Chromosome video ahead of World Down Syndrome Day on Wednesday.
Julie Britton, from Leeds - who is featured in the video with her daughter Connie-Rose Seabourne - said: "It's gone a bit crazy.
"We just wanted to dispel the myths about Down Syndrome and put a positive message out there.
"People with Down Syndrome live happy lives and go on to get jobs and have relationships."
She said: "My daughter's only four but she's in mainstream school, she's got absolutely loads of friends. It's just not like it was years ago."
Ms Britton said her daughter's school showed the video and all her friends loved it.
The families involved say they are determined to promote a positive message about Down Syndrome to the public but also to health professionals.
Ms Britton said there were concerns about a new advanced test for pregnant women which is being introduced, amid fears it could mean a rise in terminations and a dramatic drop in the number of children with Down Syndrome.
She said: "I think everybody should have the right to know and the right to make a decision.
"It's more about what they do with that information and what they are told by the professionals."
The video was the idea of Rebecca Carless, from Coventry, who contacted other members of an online support group after seeing another featuring Makaton signing.
Ms Carless told ITV's This Morning: "We wouldn't change our children but we'd change the world for them."