By Alexis Tereszcuk - Breaking Celebrity News Senior Reporter

Tennis champion Venus Williams abruptly pulled out of the U.S. Open tennis tournament on Wednesday, claiming it was because of an autoimmune disease she has recently been diagnosed with.

“I’m really disappointed to have to withdraw from this year’s U.S. Open,” Williams said in a statement from Flushing Meadows, New York.  She then revealed the shocking news about her medical illness: “I have recently been diagnosed with Sjögren’s Syndrome, an autoimmune disease which is an ongoing medical condition that affects my energy level and causes fatigue and join pain.”

The 31-year-old is a seven-time Grand Slam champion, but she has struggled with health problems this year.  She has only played four tournaments so far and a viral illness and abdominal injury kept her sidelined most of the year.

Sjögren’s is a disease that attacks the body’s moisture glands with white blood cells and causes various symptoms ranging from dry mouth to debilitating fatigue, according to the Sjögren’s Syndrome Foundation website.