A polymorphism (PM) in the microsatellite of the promoter region of matrix metalloproteinase 9 (MMP-9), modulating its expression,
could play a role in susceptibility to multiple sclerosis (MS). MMP-9 PM was determined in 95 patients with MS (MS Group) and 95 ageand
sex-matched controls (Control Group). Comparison of allelic frequencies showed that a higher number of CA repeats characterized
the MS group ( P < 0.0001) and prevalence of carriers of z22 CA repeats was higher in the MS than in the Control Group (OR 3.4, 95%
CI: 1.7–6.8, P < 0.0001). An earlier age at disease onset was a characteristic of patients with >22 CA repeats (33F10 vs. 28F10,
P= 0.027). No differences were found in the main MRI parameters.
