Shared psychotic disorder is a rare entity characterized by the transmission of delusional symptoms from one patient ("inducer") to another ("induced" partner). We here report a clinical observation of atypical shared psychotic disorder involving delusion of persecution and of grandeur in a teenager induced by two subjects (grand-father and paternal uncle) with two different types of psychiatric disorders, all of which present in the same subject (third-party). The nature of the content transmitted to the third subject was the sum of the ideas of the first two subjects. These three subjects had a close relationship and lived in a closed environment, without access to the outside world.