Medical Genetics In ancient times, abnormalities were seen as warnings or punishments from the gods. Even quite recently, it was believed that specific events during the pregnancy such as being frightened by a mouse would lead to specific defects in the baby eg a mouse shaped birth mark. Such folk beliefs still persist in placesMedical Genetics In ancient times, abnormalities were seen as warnings or punishments from the gods. Even quite recently, it was believed that specific events during the pregnancy - such as being frightened by a mouse - would lead to specific defects in the baby, eg a mouse shaped birth mark. Such folk beliefs still persist in places