Based on the extant literature, our main hypothesis was that, in adolescents who sustained a recent concussion (up to 10 days), lower fiber collinearity in major white matter tracts previously reported to be abnormal following concussion, namely ILF, IFOF, and UF, would be associated with prolonged recovery (symptoms persisting after 4 weeks of injury). The gene discussed is FOXK2; the disease is concussion.