Association studies of MMP-9 in Parkinson's disease and amyotrophic lateral sclerosis

Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS) share several clinical and neuropathologic features, and studies suggest that several gene mutations and polymorphisms are involved in both conditions. Matrix metalloproteinase-9 (MMP-9) is implicated in the pathogenesis of PD and ALS, and the C(-1562)T polymorphism in the MMP-9 gene leads to higher promoter activity. We therefore investigated whether this polymorphism predisposes to both PD and sporadic ALS (sALS). Samples from 351 subjects with PD and 351 healthy controls from two major cities in China were compared, while samples from 226 subjects with sALS were compared to the same number of controls from three centers in China. A possible association between the C(-1562)T polymorphism in the MMP-9 gene and PD or sALS was assessed by restriction fragment length polymorphism (RFLP) analysis. Our results show a significant association between the C(-1562)T polymorphism in the MMP-9 gene and risk of PD (odds ratio = 2.268, 95% CI 1.506-3.416, p<0.001) as well as risk of sALS (odds ratio = 2.163, 95% CI 1.233-3.796, p = 0.006), supporting a role for MMP-9 polymorphism in the risk for PD and sALS.