Notes • July 2, 2025by johnataylor on TwosInteresting Facts—Rare Diseases Edition: Auto-brewery syndrome (ABS), or "gut fermentation syndrome," is a disease in which a person's intestines produce alcohol. Symptoms include intoxication, sugar cravings, bloating, and problems with concentration. The ribbon color for rare diseases is the zebra print. Medical students are usually taught the phrase, "If you hear hoofbeats, think horses, not zebras," which means they should consider common conditions first. So, patients with rare diseases are the zebras rather than the horses. Rare Disease Day takes place on the last day of February, either the 28th or the 29th—the rarest calendar day—to highlight the nature of the diseases. A disease is considered rare if it affects fewer than 1 in 2,000 people. Drugs that are used to treat rare diseases are called "orphan drugs." These drugs are typically very costly to produce. Genetic mutations cause about 80% of what are considered "rare" diseases, which can then be inherited. Approximately 10% of rare diseases arise spontaneously. People with foreign accent syndrome (FAS) suddenly begin speaking with a noticeable change to their accent that listeners often interpret as “foreign.” This condition is so rare (only 100 cases have been reported since 1907) that doctors originally thought the patients were delusional. But in 2002, scientists at Oxford University discovered that FAS sufferers shared similar brain abnormalities that caused changes to their speech pitch and syllables.