This rare autoimmune disease is caused by a mutation in a single gene. In the malady, a victim's immune system attacks hormone-producing organs such as the pancreas and the thyroid, parathyroid, and adrenal glands, often rendering them nonfunctional. People with APECED also often suffer from chronic fungal infections in their mouths and other mucous membranes, and hair loss.
The search for the gene began in Finland, whose isolated population has often been studied for its elevated rate of rare genetic diseases. 14 Finnish families with 23 members afflicted with APECED were the subjects of the investigation. The discovery of the gene was announced in 1997.