Cowden syndrome is a genetic disorder related to germline PTEN variants and characterized by increased risk of cancers. These patients sometimes show behaviors considered as maladapted to social norms and conventions. We collected data on 15 patients from a single center in France. We analyzed their abilities in social cognition, considered as cognitive processes involved in our interpersonal relationships. We found an impairment in social context understanding, facial emotion recognition and fine dexterity in most of patients. This study highlights for the first time the presence of social cognition disability and the need for specific treatments and rehabilitation to improve the quality of life of these patients. (Dr. Clément Desjardins, https://jmg.bmj.com/content/early/2021/12/21/jmedgenet-2021-107954 )