Tatiana Schlossberg, the daughter of Caroline Kennedy and Edwin Schlossberg and granddaughter of John F. Kennedy, has revealed her terminal cancer diagnosis in an essay published by The New Yorker on Saturday.

The 35-year-old has acute myeloid leukemia, with a rare mutation called Inversion 3.

Schlossberg said she was diagnosed on May 25, 2024, the same day she gave birth to her second child. Hours after delivery, her doctor noticed her abnormally high white-blood-cell count and moved her to another floor for further testing.

She initially dismissed the possibility of cancer and was stunned when the diagnosis was confirmed, saying she had considered herself "one of the healthiest people" she knew.

“This could not possibly be my life,” she wrote.

Acute myeloid leukemia (AML) is a cancer that starts in the bone marrow and quickly moves into the blood, according to the American Cancer Society (ACS). General symptoms include weight loss, fatigue, fever, night sweats and loss of appetite.

There are several subtypes of AML that are important in determining a person's prognosis, according to the ACS. Schlossberg's subtype —an inversion of chromosome 3 — is listed as an unfavorable abnormality of AML on the ACS website.

Schlossberg spent five weeks at Columbia Presbyterian after her daughter’s birth before her blast-cell count dropped enough for her to begin chemotherapy at home. Her care later moved to Memorial Sloan Kettering, where she underwent a bone-marrow transplant and spent more than 50 days before returning home for more treatment.

In January, Schlossberg joined a clinical trial for CAR T-cell therapy. She wrote that much of the treatment unfolded from her hospital bed as her cousin, Robert F. Kennedy Jr., was nominated and confirmed as secretary of health and human services, a role she believes he was unqualified for.

Schlossberg thanked her husband and her family for their support and for countless days spent at her bedside.

“My parents and my brother and sister, too, have been raising my children and sitting in my various hospital rooms almost every day for the last year and a half,” she added.

Her brother, Jack Schlossberg, announced earlier this month that he is running for Congress. The 32-year-old is running for the New York City seat that has long been held by Democratic Rep. Jerry Nadler, who in September announced he will not seek re-election.

Despite all of Tatiana Schlossberg’s treatments, she said, the cancer continued to return.

“During the latest clinical trial, my doctor told me that he could keep me alive for a year, maybe,” she wrote. “My first thought was that my kids, whose faces live permanently on the inside of my eyelids, wouldn’t remember me.”

Schlossberg is now trying her best to be in the present with her children.

By profession a writer, for several years Schlossberg was a reporter for the science section of The New York Times, where she covered climate change and the environment.

Schlossberg’s essay comes on the 62nd anniversary of her grandfather’s assassination, adding her diagnosis to a long history of tragedy within the Kennedy family.

John F. Kennedy’s son, John F. Kennedy Jr., and his wife, Carolyn Bessette Kennedy, died in a plane crash in 1999.

Ethel Kennedy, the widow of Robert F. Kennedy Sr., who was assassinated in 1968, died in October 2024 of complications from a stroke. She was 96.

This article was originally published on NBCNews.com