Patty Duke, Oscar-winning American actress, dies at 69
As well as a best supporting Oscar, Duke won an Emmy in 1980 for playing Helen Keller's teacher in a TV movie.
Duke also starred in The Patty Duke Show in the 1960s in which she took the roles of "identical" teenage cousins.
She was the mother of actor Sean Astin, who played the hobbit Sam in the Lord of the Rings trilogy of films.
Her representative, Mitchell Stubbs, said in a statement that she had died early on Tuesday of sepsis from a ruptured intestine.
She underwent a heart bypass in 2004.
Mr Stubbs said: "She was a wife, a mother, a grandmother, a friend, a mental health advocate and a cultural icon. She will be missed."