Fatal Familial Insomnia is a rare and debilitating genetic disorder that affects the brain's ability to regulate sleep patterns. The condition is also known as FFI and has been linked to a specific mutation in the PRNP gene. There are numerous synonyms used for FFI, including familial fatal insomnia, insomnia fatal familial, hereditary fatal insomnia, and autosomal dominant fatal familial insomnia. The symptoms of this disease include severe sleep disturbances, which eventually lead to dementia and death. As there is no known cure for FFI, treatment focuses on managing symptoms and enhancing comfort.