Type I interferonopathies are monogenic autoinflammatory diseases induced by constitutive activation of type I interferon. Here, we provide an overview of these diseases and describe underlying molecular pathways, related phenotypes, suggestive clinical signs and investigations for helping diagnosis process and therapeutic management.Recent genetic and functional discoveries have enabled deciphering mechanisms involved in the pathogenesis of the type I interferonopathies and considering promising targeted treatments, such as JAK inhibitors, both for monogenic and multifactorial interferon-related diseases. The concept of the type I interferonopathies rests on the assumption that some diseases arise from a disturbance of interferon signalling pathway. In the presence of suggestive clinical signs (especially involving the central nervous system and the skin), a consistent positive type I interferon assessment is a further point in favour of genetic investigations in patients. This review also highlights the potential value of targeted therapeutics that should improve features of type I interferonopathies, thereby providing a validation of the underlying hypothesis.