The 53-year-old director has been suffering from a type of amyloidosis, a group of rare diseases characterized by a buildup of abnormal protein deposits in one or more organs. Bass's kind, primary amyloidosis, is the most common and originates in the bone marrow, which controls the production and recycling of antibodies. Under 2,000 new cases are reported annually.
Primary amyloidosis inhibits the breakdown of antibodies, leading to protein accumulation in the blood and deposit in organs and tissues. Because the disease shares its symptoms with several others, Bass was initially diagnosed in January with heart failure after months of day-to-day fatigue and shortness of breath.
Another doctor realized it could be amyloidosis and so directed him to the New York Presbyterian Hospital Transplant Institute. There Bass was diagnosed with the disorder and given the go-ahead for a heart transplant, waiting less than two months for a heart from a teen matching his body size and rare blood type.
Despite complications, the disease has not spread and the new organ has not been rejected.
"Having a new heart has changed everything," Bass told The New York Times. "I've just begun rehearsing again, and all of the sensations, whether they be as a musician or as a person — everything is different."
Bass will finish his medical treatment with chemotherapy and a stem-cell transplant next month in a clinical trial at Memorial Sloan Kettering Cancer Center. Once fatal in over 95% of patients, amyloidosis saw a breakthrough in 1994 with stem-cell ransplants, which along with chemotherapy is its most aggressive course of treatment.
After being cured, he intends on organizing Collegiate Chorale concerts to broaden public understanding of the disease.
"I would like people to know that you can kick it," said Bass. "It's just not necessary that anyone be misdiagnosed anymore."