Injuries in sports are the most common causes where athletes are forced to change their training plans temporarily, or more, to interrupt trainings and competitions for a certain time. Several genome-wide association studies have concluded that variations in DNA sequence interacting with non-genetic risk factors may play an important role in the etiology of injuries, including overuse injuries.
PURPOSE: To identify potential loci (chromosomal regions) that are associated with the tendinopathy of Achilles and patellar tendons.
METHODS: Study group consisted of 121 elite athletes (21 females and 100 males), current and former Estonian national team members, in the age range 27.5±5.1 years, involved in 16 different sports. The case group (n=42) consisted of athletes with patellar and Achilles tendinopathies, and the control group (n=79) was formed by athletes without these injuries. The electronic health record system was used to find clinical diagnoses of the respective injuries of the athletes participating in this study. Peripheral venous blood samples for DNA extraction and genotyping for known SNPs (SNP arrays) from all study subjects were collected. The comparison of allelic frequencies of these SNPs was made between cases and controls. For statistical analysis, we used the software PLINK. To estimate the magnitude of the effectiveness OR was used to estimate the magnitude of the effectiveness, and p-values for the significance of ORs were calculated using the χ2 - test. The p value of 10^-8 was set as a threshold for genome-wide statistical significance. To display significant SNPs, the Manhattan plot was used.
RESULTS: Association analysis revealed 2 genes that could be important as risk factors for investigated injuries, the PAPPA2 (chr 1: rs1158045, OR 13.8, p= 1.64·10^-5) and the GNG12 (chr 1: rs28435277 OR 13.8, p=1.64·10^{- 5}) with the p-value remaining at the level of \"suggestive significance\" (p=5·10^-5).
CONCLUSIONS: Our study results identified suggestive significance in allelic differences of PAPPA2 and GNG12 between case and control groups. It is important to continue with further research of genetic risk profile to understand the biological processes associated with injury risk.