Academy Award-winning actress Patty Duke passed away at the age of 69, her manager confirmed Tuesday. Duke served as president of the Screen Actors Guild for three years in the late 1980s. The Patty Duke Show ran for 104 episodes over three seasons. Duke played Helen Keller in The Miracle Worker when she was 12 years old. She won an Oscar three years later when she reprised her role in the play's film adaptation.