APOE, APOE promoter, and tau genotypes and risk for concussion in college athletes

Objective: To investigate associations of APOE, APOE promoter (G-219T), and tau protein exon 6 polymorphisms ((His)47(Tyr) and (Ser)53(Pro)) and a history of self-reported concussion in college athletes. Design: Multi-center cross-sectional study. Setting: Male football and male and female soccer programs at the University of South Carolina, Jacksonville University, Benedict College, and the College of Charleston. Participants: Active 18- to 30-year-old (n = 195) intercollegiate male football players and male and female soccer players during 2001 and 2002. Assessment of Risk Factors: Written questionnaires and blood or mouthwash samples for DNA for genotyping by RFLP/PCR. Main Outcome Measurement: Self-reported history of concussions over the previous 8 years. Results: A statistically significant, nearly 3-fold increase in risk of a history of concussion for those with the APOE promoter G-219T TT genotype relative to the GG genotype (OR, 2.8; 95% CI, 1.1 to 6.9) adjusted for age, sport, school, and years in their primary sport a finding that was stronger for Cantu grade 2 and 3 concussions. Conclusions: These results suggest that college athletes with an APOE promoter G-219T TT genotype may be at increased risk for having a history of concussions, especially more severe concussions. Although there was some support for the possibility that the tau (Ser)53(Pro) polymorphism may be associated with increased risk of prior concussion (OR, 2.1; 95% CI, 0.3 to 14.5), there was no support for an association with APOE genotypes. The results of this crosssectional study support the need for a prospective study of genetic factors, such as APOE promoter polymorphisms, and the incidence of and sequelae from concussions in college athletes.