Fatal Familial Insomnia (FFI)
Here's your citation in American Psychological Association (APA) format:
Fatal Familial Insomnia (FFI). (n.d.). In Alleydog.com's online glossary. Retrieved from: https://www.alleydog.com/glossary/definition-cit.php?term=Fatal+Familial+Insomnia+%28FFI%29