TMZ: Danny Gans died in his sleep early this morning, after a family member called 911 to say Danny was having trouble breathing. By the time paramedics arrived, he was dead.

A ticket rep at Steve Wynn's Encore hotel tells us they just got the call and the entire staff is "shocked and upset."

Gans is a legend in Las Vegas -- the self described "musical impressionist" signed a $150 million contract in 2000.

We're told Gans died at 3:00 AM at his home in Vegas. There are reports his wife discovered his body and called for help.

Gans was named "Las Vegas Entertainer of the Year" a record 11-times in a row. He did not perform last night.

Besides being a gifted entertainer, Gans was a pretty good athlete -- in fact, he was drafted by the KC Royals out of high school and played minor league ball.

UPDATE: TMZ has learned a 911 call was made by a family member at 3:44 AM for a 52-year-old man who was "having trouble breathing." By the time medics arrived, Gans had already passed away.

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