The Role of Aquaporin-4 Polymorphisms in the Development of Brain Edema After Middle Cerebral Artery Occlusion.

The Role of Aquaporin-4 Polymorphisms in the Development of Brain Edema After Middle Cerebral Artery Occlusion.

Stroke. 2008 Feb 28

Ilka Kleffner MD*; May Bungeroth; Hagen Schiffbauer MD; Wolf-Ruediger Schäbitz MD; E. Bernd Ringelstein MD; and Gregor Kuhlenbäumer MD
From the Departments of Neurology (I.K., W.R.S., E.B.R., G.K.), and Clinical Radiology (H.S.), and the Leibniz-Institute of Atherosclerosis Research (M.B., E.B.R., G.K.), University of Münster, Münster, Germany.

* To whom correspondence should be addressed. E-mail: kleffnil@uni-muenster.de

BACKGROUND AND PURPOSE: Some patients develop severe brain edema after complete middle cerebral artery occlusion, whereas others do not. Aquaporin-4 (AQP4) is the main water channel in the brain and has been shown to be critical for the development of brain edema after ischemia. We asked whether genetic variation in the AQP4 gene is related to the severity of brain edema after middle cerebral artery occlusion.

METHODS: We genotyped 10 single nucleotide polymorphisms distributed across the AQP4 gene in 41 patients with middle cerebral artery occlusion with and without severe brain edema and assessed single marker association as well as the linkage dysequilibrium structure across AQP4.

RESULTS: One single nucleotide polymorphism (rs9951307) at the 3' end of AQP4 was associated with severe brain edema (dominant model, P=0.01; OR, 0.10; 95% CI, 0.02 to 0.49 for the protective G-allele). Linkage dysequilibrium across AQP4 was low; no clear haplotype blocks could be identified for the assessment of haplotype association.

CONCLUSIONS: This explorative study shows that genetic variation in AQP4 might contribute to brain edema formation after middle cerebral artery occlusion and warrants further investigation.

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