An rs13293512 polymorphism in the promoter of let-7 is associated with a reduced risk of ischemic stroke.

The expression of let-7 family members was differentiated in ischemic stroke (IS), functioning as an important regulating molecular in the pathophysiology of stroke. We hypothesized that genetic polymorphism in the promoters of let-7 family may be associated with the risk of IS. To test this hypothesis, we investigated the association of the rs10877887 and rs13293512 in the promoters of let-7 family with the susceptibility to IS. A hospital-based case-control study was performed. The rs10877887 genotype was determined by using a polymerase chain reaction-restriction fragment length polymorphism assay, and the rs13293512 genotype was determined by using a TaqMan assay. We found that the rs13293512CC genotype was associated with a reduced risk of IS (CC vs. TT: adjusted OR = 0.43, 95 % CI 0.26-0.71; dominant model: adjusted OR = 0.70, 95 % CI 0.49-0.98; recessive model: adjusted OR = 0.45, 95 % CI, 0.28-0.73). Stratification analysis showed that the rs10877887TT carriers had a higher level of total cholesterol compared to rs10877887TC/CC carriers (P = 0.03). Combined analysis showed that the rs10877887TC/CC and rs13293512TC/CC genotypes had a reduced risk of IS risk (adjusted OR = 0.58, 95 % CI 0.36-0.95). Our findings suggest that the rs13293512 polymorphism may be a protective factor for the development of IS.