Impact Of Alpha Enac Polymorphisms On The Risk Of Ischemic Cerebrovascular Events: A Multicenter Case-Control Study

Background: Amiloride-sensitive epithelial sodium channels (ENaCs) are important candidates in the development of hypertension, which is a major risk factor for stroke. Two single-nucleotide polymorphisms (SNPs) in the gene that encodes the ENac alpha-subunit (alpha ENaC) have been identified. We evaluated those SNPs for a possible association with ischemic cerebrovascular events (ICEs).Methods and Results: We genotyped 1399 patients with ICEs [median age, 70 years; interquartile range, 58-78 years; 745 (53%) men] and 1076 control individuals without vascular disease [47 (39-58) years; 557 (52%) men] for the SNPs Trp493Arg and Ala663Thr. The SNP frequencies at nucleotide 3977 (Trp493Arg) in the aENaC gene were significantly different in patients and controls. Carriers of 493Arg had a 1.78-fold increased risk (95% confidence interval, 1.02-3.12) for ICEs compared with Trp/Trp carriers. Interaction analysis revealed that the relative risk was even higher in women in the lowest age tertile [adjusted odds ratio, 3.26 (1.109.72)].Conclusions: Carriers of the 493Arg allele are at increased risk for ICEs compared with Trp/Trp carriers. The effect is independent of traditional vascular risk factors and is particularly evident in younger women. The TrP493Arg variant in alpha ENaC may represent an important candidate genetic susceptibility factor in the development of ICEs. (c) 2005 American Association for Clinical Chemistry