Celine Dion: Stiff person syndrome leaves My Heart Will Go On singer with "no control" of her muscles

Celine Dion's older sister has shared a heartbreaking update on her condition.

Last year, the 55-year-old singer revealed she had been diagnosed with an incurable neurological condition, known colloquially as "stiff person syndrome". This led her to cancel all upcoming tour dates, including the remainder of her world tour.

Dion said at the time: "It’s not fair to you to keep postponing the shows, and even though it breaks my heart, it’s best that we cancel everything now until I’m really ready to be back on stage again."

Now, her sister Claudette has spoken to Canada's 7 Jours - and explained how the rarity of the condition means not much work is being done into finding a cure.

She said: "The vocal cords are muscles, and the heart is also a muscle. This is what comes to get me. Because it’s one out of a million case, the scientists haven’t done that much research because it didn’t affect that many people.

"Some people have lost hope because it’s an illness that isn’t well known. If only you knew the number of phone calls the foundation gets about Celine. People tell us they love her and they’re praying for her. She gets so many messages, presents and blessed crucifixes."