Celine Dion's sister says there's 'little' anyone can do to relieve singer's pain

Celine Dion was diagnosed with stiff-person syndrome in December. Photo: Celine Dion/Instagram

Despite the best efforts of her physicians and loved ones, Celine Dion is struggling to find relief from the debilitating pain caused by the rare disorder that has kept her from performing over the past year.

"It's an illness we know so little about," said Claudette, the sister of the My Heart Will Go On singer, who has served as Dion's spokesperson in recent months.