Proinflammatory gene polymorphisms and ischemic stroke.

Despite recent advances in acute stroke therapy, stroke remains the leading cause of severe disability and the third leading cause of death, after heart disease and cancer, in Western countries and Japan. The identification of biomarkers of stroke risk is thus important both for risk prediction and for intervention to avert future events. Although genetic linkage analyses of families and sib-pairs as well as candidate gene and genome-wide association studies have implicated several loci and candidate genes in predisposition to ischemic or hemorrhagic stroke, the genes that contribute to genetic susceptibility to these conditions remain to be identified definitively. Given that vascular inflammation has been recognized as an important mechanism of atherosclerotic disease, proinflammatory genes may play pivotal roles in the pathogenesis of ischemic stroke. In this review, we summarize candidate genes that have been implicated in common forms of ischemic stroke by linkage analyses and association studies. We also review in more detail studies that have revealed an association of ischemic stroke with polymorphisms of proinflammatory genes of particular interest (LTA, IL6, and ALOX5AP) as well as with polymorphisms at chromosomal region 9p21.3, which has recently been identified as a susceptibility locus for coronary heart disease. Such studies may provide insight into the function of implicated genes as well as into the role of genetic factors in the development of ischemic stroke.