Tennis champion Venus Williams and musicians Halsey and Solange Knowles have one big thing in common — and it’s not just their positions at the top of the celebrity food chain. Despite the physical demands of their careers, all three have been vocal about receiving the same autoimmune disorder diagnosis and the fatigue and joint pain that comes with it. For Williams, her challenging road to a diagnosis forced her to take a break from tennis in 2011 . Over the last decade, Halsey and Knowles