Genetic Causes of Cerebral Small Vessel Diseases: A Practical Guide for Neurologists.

Cerebral small vessel disease (CSVD) includes various entities affecting the brain and, often, systemic small arteries, arterioles, venules, and capillaries. The underlying causes of CSVD are different, and some of them are genetic. Monogenic CSVD are responsible for 1-5% of all strokes and for several other disturbances. Despite many genes being involved, the phenotypes of monogenic CSVD partly overlap. Given that the genetic testing for different diseases can be challenging and time-consuming, the practicing neurologist should be adequately informed of the genetic background of CSVD and should be able to select patients to undergo genetic assessment as well as the genes to be analyzed. The purpose of this review is to summarize clinical, neurological and non-neurological, and neuroimaging features of monogenic CSVD, and to provide a flowchart to be used in clinical practice to guide neurologists in this field. The proposed flowchart and the relative tables can be applied to three different settings, depending on the presentation: 1) ischemic stroke and/or transient ischemic attack; 2) cerebral hemorrhage; 3) other neurological, non-neurological and/or neuroimaging features of monogenic CSVD, in absence of stroke syndromes due to infarction or hemorrhage.