Los Angeles: Oscar-winning actress and singer Patty Duke died on Tuesday. She was 69.

Duke won an Oscar when she was just 16 for her portrayal of deaf-blind political activist Helen Keller in "The Miracle Worker." Duke's real name was Anna Pearce.

Duke's manager Mitchell Stubbs said in a statement that she had developed sepsis from a ruptured intestine, her "This morning, our beloved wife, mother, grandmother, matriarch and the exquisite artist, humanitarian, and champion for mental health Anna Patty Duke Pearce closed her eyes, quieted her pain and ascended to a beautiful place," said her son, the actor and director Sean Astin.

Astin added the family were celebrating the "infinite love and compassion she shared through her work and throughout her life."

Duke earned fame after winning a best supporting actress Academy Award for her role as Keller in Arthur Penn's 1962 biopic "The Miracle Worker." She went on to became a good actor by playing "identical cousins" in her own sitcom, "The Patty Duke Show," which ran for more than 100 episodes in the mid-1960s.

She acted in some more films too, including in Mark Robson's 1967 drama "Valley of the Dolls." After tasting success in acting, Duke embarked on a successful singing career. She also served as president of the Screen Actors Guild from 1985 to 1988. Duke won three Emmy Awards, including for the miniseries "Captains and Kings" and television movie "My Sweet Charlie," which both aired in the 1970s.

Duke released her autobiography in 1987 and at that time she revealed that she had been diagnosed with bipolar disorder. In 2011, she became a vocal advocate for people with mental health issues. Few days ago, Duke had apologized to fans for having kept a low profile recently. "I have been absent, but not far, believe me. I love and miss you all. Hopefully back more soon and often," tweeted the star.

"My mother's life touched tens of millions of people. Her groundbreaking portrayal of iconic American legend Helen Keller launched a career that would span six decades," said Astin.