The myotendinous junction (MTJ) is at high risk of muscle injury, and the collagen XXII is strictly expressed at tissue junctions, specifically at the MTJ. We investigated the hypothesis that single nucleotide polymorphisms (SNPs) related to collagen type XXII alpha 1 chain gene (COL22A1) mRNA expression are associated with susceptibility to muscle injury in athletes. History of muscle injury was assessed in 3,320 Japanese athletes using a questionnaire, and two expression quantitative trait loci (eQTL) SNPs for COL22A1 (rs11784270 A/C and rs6577958 T/C) were analyzed using the TaqMan® SNP Genotyping Assay. rs11784270 (Odds ratio [OR] = 1.80, 95% confidence interval [CI] = 1.27-2.62, P=0.0006) and rs6577958 (OR = 1.45, 95% CI = 1.10-1.94, P=0.0083) were significantly associated with muscle injury under A- and T-allele additive genetic models, respectively. These results suggest that the expression level of COL22A1 at the MTJ influences muscle injury risk in athletes.
Keywords: COL22A1; muscle injury; myotendinous junction; rs11784270; rs6577958.