Patty Duke, the child star who won an Oscar at the age of 16 and went on to star in a self-titled sitcom, has died at the age of 69.

Her representative, Mitchell Stubbs, released this statement: "Anna 'Patty Duke' Pearce passed away this morning March 29, 2016 at 1:20 am. Her cause of death was sepsis from a ruptured intestine. She was a wife, a mother, a grandmother, a friend, a mental health advocate and a cultural icon. She will be greatly missed."

Duke, born with the name Anna Marie in Queens, New York, began acting at the age of 8, in soap operas and a television adaptation of the musical "Meet Me In St. Louis." She went on to star as Helen Keller in Broadway's "The Miracle Worker," then reprised the role in the film version.

For that performance, she won the Academy Award for Best Supporting Actress at the age of 16; she was the youngest person at the time to win an Oscar in a competitive category. Afterward, she starred in her own ABC sitcom, "The Patty Duke Show," as a pair of identical cousins.

She worked steadily in television for the new few decades, primarily in TV movies, including "My Sweet Charlie" and "Captains and Kings," for which she won Emmy Awards. In recent years, Duke had cameos in shows like "Hawaii Five-0" and "Glee."

Duke married four times and had one biological child, the actor Sean Astin. She was an advocate for mental health, after admitting she was diagnosed as bipolar in her autobiography, "Call Me Anna."

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