Doctors Thought They Knew What a Genetic Disease Is. They Were Wrong.

In the summer of 2018, 59-year-old David Gould went for his annual checkup, expecting to hear the usual: Everything looks fine. Instead, he was told that he was newly—and oddly—anemic.

Two months later, Gould began to experience a strange cascade of symptoms. His ankles swelled to the width of his calves. The right side of his face became so bloated that he could not open his eye. He developed a full-body rash, joint pain, fever, and drenching night sweats. His anemia worsened, and he was requiring frequent blood transfusions. Gould’s physicians were baffled; he was scared. “I started to get my will and affairs in order,” he told me.