Katy Perry sends touching message to dying fan

Katy Perry has honoured a terminally ill 13-year-old girl's dying wish by sending her a video message.

Sophie Birtles suffers from Juvenile Sandhoff disease, an extremely rare incurable degenerative condition that causes loss of hearing, movement, sight and speech. She has been looked after at Rebecca House Hospice in the Isle of Man, U.K., for the past fortnight.

Her friends and relatives have been rallying around Sophie, with family friend Jo Pack determined to honour one of Sophie's final wishes to get a message from her idol Katy.

Jo launched a Twitter campaign using the hashtag #YoureAFireworkSophie in a bid to get Katy's attention, and it quickly went viral. In fact, on Saturday night (30Apr16), it was trending above even Britain's Got Talent - one of the U.K.'s favourite television shows.

And the hard work paid off, as on Monday (02May16), Jo shared a video that Firework singer Katy had sent to Sophie.

In the footage, Katy says: "Hi Sophie, it's Katy Perry here. I heard your story and I just wanted to tell you that you are a firework, and you are trending, and I do love you and everybody loves you and we're thinking about you all over the world right now and sending you so much love - I hope you can feel it through this message. Love you Sophie."

Jo also shared a video of Sophie watching the video. Although her condition means she's not able to respond in the way she would perhaps have liked, the teenager is seen blowing a kiss to the computer screen after seeing Katy's message.

"I'm in tears right now xxxxx job done - thank u 2 everyone #YoureAFireworkSophie," Jo tweeted on Monday.

Every year, between two and six children are born with Juvenile Sandhoff disease in the U.K.