The Influence of the Apolipoprotein E (APOE) Gene on Subacute Post-Concussion Neurocognitive Performance in College Athletes.

OBJECTIVE

The purpose of this study was to determine whether the ε4 allele of the APOE gene influences neurocognitive outcome following sports-related concussion. It was hypothesized that participants with an ε4 allele would show poorer neurocognitive performance and greater neurocognitive variability than those without an ε4 allele.

METHOD

Participants included 57 concussed collegiate athletes (77.2% male) who participated in a concussion management program at a large university. All athletes underwent a comprehensive neuropsychological assessment and provided a DNA sample for determination of their APOE genotype. The test battery included measures sensitive to concussion, covering the broad domains of learning and memory, attention, processing speed, and executive functions.

RESULTS

The sample was divided into ε4 + (n = 20) and ε4 - (n = 37) groups. No significant differences were found between athletes with and without an ε4 allele when examining mean neurocognitive standardized scores (all p > .05; d = 0.16-0.18). However, athletes with an ε4 allele were more likely to show a greater number of impaired neurocognitive scores post-injury compared to athletes without an ε4 allele, χ2(1, N = 57) = 3.96, p = < .05, φ = 0.26. Additionally, athletes with an ε4 allele demonstrated greater neurocognitive variability than athletes without an ε4 allele, t(55) = -2.04, p < .05, d = 0.53.

CONCLUSIONS

This research furthers our understanding of how genetic factors uniquely contribute to neurocognitive performance differences following concussion. Our findings suggest a possible relationship between the ε4 allele and post-concussion impairment, as well as between the ε4 allele and neurocognitive performance variability, suggesting that the ε4 genotype may be a risk factor for less efficient cognitive processing in concussed athletes.