AceShowbiz - Celine Dion no longer can "control" her muscles. The "My Heart Will Go On" hitmaker axed her world tour in December 2022 after being diagnosed with stiff person syndrome - an uncurable neurological condition - and while her "goal" is to return to the stage one day, her sister Claudette Dion, 74, suggested it seems unlikely at the moment.

"She's working hard, but she doesn't have control over her muscles. What breaks my heart is that she's always been disciplined. She's always worked hard. Our mother always told her, 'You're going to do it well, you're going to do it properly.' It's true that in both our dreams and hers, the goal is to return to the stage. In what capacity? I don't know," Claudette said to Canadian website 7 Jours.

While research is ongoing into the condition, the rarity of it means progress has been slow. Claudette added, "The vocal cords are muscles, and the heart is also a muscle. This is what comes to get me. Because it's 1 out of a million case, the scientists haven't done that much research because it didn't affect that many people."

Celine's family charity, Fondation Maman Dion, has been inundated with messages of support for the star. Claudette said, "Some people have lost hope because it's all 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."

Claudette has previously revealed that despite working with "the top researchers in the field," her 55-year-old sister has seen little improvement in her health. She told Le Journal de Montreal, "We can't find any medicine that works, but having hope is important."