Former Supreme Court Justice Sandra Day O'Connor says she has been diagnosed with "the beginning stages of dementia, probably Alzheimer's disease," in an open letter that was released Tuesday.

O'Connor, the first female justice on the high court, says she will withdraw from public life.

She received the diagnosis "some time ago," O'Connor said, in a letter released by the Supreme Court's public information office.

"As this condition has progressed, I am no longer able to participate in public life," O'Connor said. "Since many people have asked about my current status and activities, I want to be open about these changes, and while I am still able, share some personal thoughts."

Toward the end of her letter, O'Connor said:

"I will continue living in Phoenix, Arizona, surrounded by dear friends and family. While the final chapter of my life with dementia may be trying, nothing has diminished my gratitude and deep appreciation for the countless blessings in my life. How fortunate I feel to be an American and to have been presented with the remarkable opportunities available to the citizens of our country. As a young cowgirl from the Arizona desert, I never could have imagined that one day I would become the first woman justice on the U.S. Supreme Court."

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