TRAGIC CELINE MAY NEVER SING AGAIN!

Losing control of vocal cords while fighting nerve disease

STRICKEN Celine Dion's ongoing battle with crippling stiff-person syndrome - an incurable neurological disease has taken a heartbreaking turn, according to sources who say the ailing vocalist fears she'll never sing for her fans again!

Claudette Dion, one of the My Heart Will Go On artist's 13 older siblings, reveals Celine, 55, is "working hard" - but "she doesn't have control over her muscles vocal cords are muscles."

Just over a year ago, Celine revealed she'd been diagnosed with the rare disorder, which causes the body to attack its own nerve cells, freezing muscles and causing spasms so violent they can shatter bones!

Determined Dion has enlisted doctors and physical therapists to help combat the condition's worst effects - but the hitmaker's sister says her prognosis is not promising.