Venus Williams out of U.S. Open after Sjogren's Syndrome diagnosis

Venus Williams of the U.S. celebrates defeating Spain's Maria Jose Martinez Sanchez at the All England Lawn Tennis Championships at Wimbledon, Friday, June 24, 2011.
AP Photo/Anja Niedringhaus
Venus Williams at Wimbledon
Venus Williams on happy day, at Wimbledon on June 24, 2011
AP Photo/Anja Niedringhaus

(CBS/AP) Venus Williams says she has Sjogren's syndrome? What's that?

That's a question tennis fans have been asking since the 31-year-old tennis ace withdrew unexpectedly from the U.S. Open on Wednesday, saying she has the autoimmune disease and that its symptoms were making it hard to play.

PICTURES - Venus Williams has Sjogren's Syndrome: What is it?

"I am thankful I finally have a diagnosis and am now focused on getting better and returning to the court soon," Williams said.

Sjogren's (pronounced SHOW-grens) is an incurable disease in which the body's white blood cells attack the salivary glands and other glands that produce moisture. It produces a wide variety of symptoms, including dry eyes and mouth and fatigue, and can be hard to diagnose.

What will having Sjogren's mean for Williams and her career?

"It does not seem life-threatening or career-ending," Dr. John Fitzgerald, director of clinical rheumatology at UCLA, who is not involved in Williams' diagnosis or treatment.

The former No. 1 ranked women's tennis player, winner of 7 Grand Slam titles, Williams was unseeded at the U.S. Open this year because of limited playing time. Since reaching the semifinals at last year's U.S. Open, Williams has played only 11 matches.

On Monday, when asked about the illness that caused her to skip tournaments this summer, Williams declinded to say what her ailment was - only that it had been diagnosed.

"It was just energy-sucking, and I just couldn't play pro tennis," she said Monday. "Just to miss so much time off tour was just disheartening. But I'm just really excited to be back."

For now, that comeback has been derailed.