Head & Brain Injury Advice and Resources


APOE-e4 allele predicts worse outcome after TBI

The APOE-e4 allele is a gene mutation associated with incresed risk of Alzheimer’s disease. Does possession of this gene mutation contribute to worse outcome following TBI? In the Journal of Neurotrauma 25:279–290 (April 2008) Zhou and colleges carried out a comprehensive survey and meta-analysis of cohort studies of sufficient rigor to determine whether the presence of the APOE4 allele contributes to poor outcome following traumatic brain injury (TBI). They 100 identified studies between 1993 and 2007 they selected 14 cohort studies for analysis based on comprehensive quality assessment. These studies included a total of 2527 participants, 736 with and 1791 without the APOE4 allele. The studies showed that possession of the APOE-e4 allele was not associated with initial injury severity of TBI.

However, the APOE4 allele was significantly associated with a poor outcome of TBI at 6 months after injury. While knowing that a victim of TBI has the gene mutation does not create any new or improved treatment options, it can explain in litigation why a mild or moderate TBI has more severe consequences than ordinarily anticipated.