Genetics of ischemic stroke: An Indian scenario.

Stroke, a heterogeneous multifactorial disorder, is known to be a major cause of death and adult disability within both the developed and developing countries. Approximately 85% of stroke cases are ischemic, whereas the remaining 15% are hemorrhagic. It is caused by multiple genetic factors, environmental factors, and interactions among these factors. Several candidate genes have been found to be associated with ischemic stroke. The most extensively studied genes include those involved in hemostasis, inflammation, nitric oxide production, homocysteine and lipid metabolism, and rennin-angiotensin-aldosterone system. Combined linkage/association studies have demonstrated that genes encoding phosphodiesterase 4D (PDE4D) and arachidonate 5-lipoxygenase-activating protein (ALOX5AP) confer risk for stroke. Even though there is substantial evidence for the genetic basis of stroke as provided by the epidemiological data from twin- and family-based studies, the contribution of genetic factors identified till now is either not enough or very less to explain the entire spectrum of encountered phenomena associated with ischemic stroke. Till date, no genome-wide association studies (GWAS) have been carried out in India. We aim to extensively review the studies on candidate genes that may have potential applications in the early diagnosis, prevention, and treatment of ischemic stroke in the Indian population. This article further emphasizes the role of GWAS in ischemic stroke and the need for an extensive GWAS in the Indian population.