Weighted total genotype score associated with knee ligament injury incidence in adolescent female basketball athletes.

backgroundAmong the genetic factors of knee ligament (KL) injury, single-nucleotide polymorphisms (SNPs) in genes encoding proteins involved in ligament structure and function have received increasing attention. However, the development of KL injury is complex and polygenic, suggesting that a single SNP may not adequately capture an individual's susceptibility. To examine whether total and weighted genotype scores are associated with KL injury incidence in adolescent basketball athletes, and whether these associations differ by sex.

methodsData from 534 Japanese basketball athletes (participation age: 15-23 years) were retrospectively analyzed. KL injuries diagnosed between the ages of 13 and 17 years were recorded, and injury incidence was calculated per 1,000 athlete-hours (AHs). Eight SNPs in collagen- and matrix-related genes were genotyped. The total genotype score (TGS) was calculated by summing genotype scores. Weighted TGS (w-TGS) was calculated by weighting the genotype scores according to SNP-specific standardized regression coefficients. Associations between genotype scores and injury incidence were examined separately according to sex.

resultsFemale athletes demonstrated a higher incidence of KL injuries than male (p < 0.001). In females, w-TGS was positively associated with KL injury (r = 0.14, p = 0.01) incidence, whereas TGS was not. Female athletes with high w-TGS (0.15, 95% CI [0.08-0.22] AHs) exhibited a significantly greater KL injury incidence than females with low w-TGS (0.05, 95% CI [0.01-0.09] AHs, p = 0.014) and males regardless of w-TGS (HIGH in female vs. HIGH in male; 0.01, 95% CI [0.00-0.03] AHs, p < 0.001, vs. LOW in male; 0.01, 95% CI [0.00-0.03] AHs, p = 0.001). No significant association was observed among males. Among the individual SNPs, COL5A1 rs13946 TT genotype was significantly associated with a higher incidence of KL injury in females (p = 0.005).

conclusionsThese findings suggest that a w-TGS derived from a candidate gene approach may be associated with an increased incidence of KL injuries in adolescent female athletes. Accounting for SNP-specific effects may enhance the characterization of adolescent sex-specific genetic susceptibility to ligament injury. The current findings are exploratory and require validation in independent cohorts before application to risk prediction or individualized prevention.