Nora Ephron, the scribe of whip-smart romantic comedies like When Harry Met Sally and Sleepless in Seattle, died Tuesday at age 71 from complications of a rare blood disorder called myelodysplasia.

The condition that claimed Ephron's life occurs when a person's bone marrow malfunctions and does not produce enough normal blood cells. It's most common in adults over the age of 50, and the condition is slightly more common in men than in women, according to St. Jude's Hospital.

There is no cure for myelodysplasia, but many patients survive for a long time after diagnosis thanks to bone marrow or cord blood transfusion. Other myelodysplasia patients receive chemotherapy in order to stop the disease from progressing to become acute myeloid leukemia, which happens in about 30 percent of patients.

Though myelodysplasia is often characterized as a kind of pre-cancer condition, it is also sometimes classified as cancer and treated with anti-cancer drugs, which explains why multiple news outlets are reporting that Ephron died of cancer. It is not certain if Ephron's condition did indeed progress to leukemia.

Patients often do not know they have myelodysplasia until it is picked up by a routine blood test since the disease does not always cause symptoms early on. Some patients experience shortness of breath, fatigue, easy bruising or bleeding, paler skin than normal and fever, according to the National Institutes of Health.

Ephron was diagnosed with the condition six years ago, according to an obituary in the Washington Post.  She is survived by her husband, screenwriter Nicholas Pileggi, and her sons Jacob and Max Bernstein.