Sjogren's Syndrome Support Group
Sjogren's syndrome is an autoimmune disorder in which immune cells attack and destroy the exocrine glands that produce tears and saliva. It also associated with rheumatic disorders such as rheumatoid arthritis, and it is rheumatoid factor positive in 90 percent of cases.
Al
http://www.dailymail.co.uk/news/article-2032492/Sjogrens-Syndrome-Venus-Williams-withdraws-US-Open.html?ito=feeds-newsxml
Saw her interview; maybe she will be a spokes person for Sjogrens.
It is not that rare not with 4Million people having it, but you are right when you said it seems rare because of the length of time for diagnosis.
Everything happens for a reason. Maybe Venus is supposed to be the spokes person for Sjogren's and she will be heard.