Book excerpt: Stroke is a major cause of death and the major cause of adult neurological disability in most of the world. Despite its importance on a population basis, research into the genetics of stroke has lagged behind that of many other disorders. However, the situation is now changing. Anincreasing number of single gene disorders causing stroke are being described, and there is growing evidence that polygenic factors are important in the risk of apparently "sporadic" stroke.Stroke Genetics provides an up-to-date review of the area, suitable for clinicians treating stroke patients, and both clinical and non-clinical researchers in the field of cerebrovascular disease. The full range of monogenic stroke disorders causing cerebrovascular disease, including ischaemicstroke, intracerebral haemorrhage, aneurysms and arteriovenous malformations, are covered. For each, clinical features, diagnosis, and genetics are described. Increasing evidence suggest that genetic factors are also important for the much more common multifactorial stroke; this evidence isreviewed along with the results of genetic studies in this area. Optimal and novel strategies for investigating multifactorial stroke, including the use of intermediate phenotypes such as intima-media thickness and MRI detected small vessel disease are reviewed. The book concludes by describing apractical approach to investigating patients with stroke for underlying genetic disorders. Also included is a list of useful websites.