The Manx cat, named after the Isle of Man, in the Irish Sea between England and Ireland, is a mutation in which a dominant gene results in taillessness. Fetuses which inherit two of these dominant genes die in the womb but those with only one may have complete or partial taillessness or sometimes a full tail. Tailless cats are therefore usually bred to Manx born with full tails to create the next generation. Unfortunately, the gene for taillessness can sometimes affect other vertebrae or lead to malfunction of the sphincter muscle.