OBJECTIVETo assess the association between matrix metalloproteinase-3 (MM-3) gene polymorphisms and subtypes of ischemic stroke (IS) in northern Han Chinese population.

METHODSA total of 289 patients with acute IS (within 3 days after the onset, including 185 with large artery atherosclerosis (LAA) and 104 for small artery occlusion (SAO)) and 175 matched healthy controls were recruited for this case-control study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or sequenc-based typing (SBT) was carried out to analyze 3 SNPs of the MMP-3 gene.

RESULTSAn incomplete linkage disequilibrium (LD) block was constructed with the 3 SNPs, and the distribution of genotypes of the 3 SNPs differed between the LAA group and controls in a dominant model: Carriers of 5A allele (5A5A+5A6A) of the rs3025058 locus were 1.72 times more susceptible to LAA stroke compared with carriers of 6A6A alleles (P=0.017, OR=1.72, 95% CI: 1.10-2.69), carriers of G alleles (GG+AG) of the rs522616 locus were 0.52 times more susceptible to LAA stroke compared with carriers of AA alleles (P=0.005, OR=0.52, 95% CI: 0.33-0.82), whilst carriers of A allele of the rs679620 locus were 1.55 times more susceptible to LAA stroke compared with carriers of GG alleles (P=0.042, OR=1.55, 95% CI: 1.01-2.37). However, no significant difference has been found between particular genotypes of such SNPs between SAO patients and controls (P> 0.05). Furthermore, 5A-A-A and 6A-A-A haplotypes were significantly more common in LAA group than the controls (P< 0.05), whilst 6A-G-G haplotype has been the opposite (P< 0.01).

CONCLUSIONOur study has demonstrated that serum MMP-3 level is significantly increased at acute stage of LAA as well as SAO type strokes. There may be an association of rs3025058, rs522616 and rs679620 of MMP-3 gene with susceptibility to LAA stoke in northern Han Chinese population.