A polymorphism at -1607 2G in the matrix metalloproteinase-1 (MMP-1) increased risk of sudden deafness in Korean population but not at -519A/G in MMP-1.

Objectives/hypothesis: Matrix metalloproteinase-1 (MMP-1) is associated with a risk of inflammatory disease and cancer invasion. Two common etiologies for sudden deafness (SD) are circulatory disturbance and inflammation. The present study aimed to investigate whether MMP-1 polymorphisms are associated with SD.

Study Design: Case-control study. Ninety-nine Korean SD patients and 530 normal patients (controls) were used in this study.

Methods: Single nucleotide polymorphism (SNP) of MMP-1 (at -1607G/2G and -519A/G) was analyzed using the pyrosequencing method.

Results: At MMP-1 -1607G/2G, the distributions of 2G/2G, G/2G, and G/G genotypes in controls were 36.8%, 44.3%, and 18.9%, respectively, and in SD patients were 46.5%, 48.5%, and 5.1%, respectively. The 2G/2G genotype was found to increase the risk of SD compared with the G/G genotype (codominant model: P = .0029; recessive model: P = .0003). The 2G allele was found to increase the risk of SD compared with the G allele (P = .002). At MMP1 -519A/G, there was no statistically significant increase in the risk of SD. Among haplotypes of MMP-1 polymorphisms -1607G/2G and -519A/G, 2GA and GA were found to be associated with SD (P < .05).

Conclusions: These results suggest that the 2G/2G genotype is associated with an increased risk of SD compared with the G/2G and G/G genotypes. Furthermore, the 2G allele may be a risk factor for SD.