The Italian region of Lombardy, with its existing stroke centers and high-technology laboratories, provides a favorable context for studying monogenic diseases associated with stroke. The Lombardia GENS project was set up to create a regional network for the diagnosis of six monogenic diseases associated with stroke: CADASIL, Fabry disease, MELAS, familial and sporadic hemiplegic migraine, hereditary cerebral amyloid angiopathy and Marfan syndrome. The network comprises 36 stroke centers and seven high-technology laboratories, performing molecular analysis. In this context, all stroke/TIA patients fulfilling clinical criteria for monogenic diseases are currently being included in an ongoing study. Demographic, clinical and family data and diagnostic criteria are collected using standardized forms. On the basis of stroke incidence in Lombardy and the reported prevalence of the diseases considered, we expect, during the course of the study, to collect datasets and DNA samples from more than 200 stroke patients suspected of having monogenic diseases. This will allow evaluation of the regional burden and better phenotype characterization of monogenic diseases associated with stroke.