5 interesting facts about the American Shorthair: the breed that is so rare that it became a Guinness World Record holder: 1.) The first American Shorthair cat was Adam, aka “Council Rock Farm Adam of Hi-Fi” 2.) Adam’s parents never had any more Shorthair kittens 3.) The rex mutation doesn’t cause their Shorthair 4.) It’s rare in its native country—it even holds a Guinness World Record for it The American Shorthair was supposedly the rarest breed on the CFA register in 2017. 5.) The texture of its fur is often compared to steel wool