ACE genotype, risk and causal relationship to stroke: implications for treatment.

The angiotensin-converting enzyme (ACE) catalyzes the formation of angiotensin II and the breakdown of bradykinin into inactive products. The insertion/deletion (I/D) polymorphism affects the activity of the enzyme, with the DD genotype being responsible for the highest activity of the enzyme. Meta-analysis of 11 studies including white persons showed that the DD genotype was a risk factor for ischemic stroke. No such correlation was found in an Asian population. Studies on different etiologies or intermediate phenotypes of ischemic stroke did not bring univocal results. There are still no convincing data on whether the I/D polymorphism of the ACE gene is a risk factor for spontaneous intracerebral hemorrhage and intracranial aneurysms, ruptured or unruptured. Several pharmacogenetic studies analyzed the influence of the ACE I/D polymorphism on the response to acute stroke therapy (thrombolysis) or prevention strategies (lifestyle modification and treatment of vascular risk factors). Presently, however, there is no consensus on whether the efficacy of these therapies is affected by the ACE gene I/D polymorphism.