Post-traumatic brain injury: genetic susceptibility to outcome

It is estimated that 2% of the population from industrialized countries live with lifelong disabilities resulting from traumatic brain injury (TBI) and roughly one in four adults are unable to return to work 1 year after injury because of physical or mental disabilities. TBI is a significant public health issue that causes substantial physical and economical repercussions for the individual and society. Electronic databases (PubMed, Web of Science, Google Scholar) were searched with the keywords traumatic brain injury, TBI, genes and TBI, TBI outcome, head injury. Human studies on non-penetrating traumatic brain injuries reported in English were included. To provide health care workers with the basic information for clinical management we summarize and compare the data on post-TBI outcome with regard to the impact of genetic variation: apolipoprotein E (APOE), brain-derived neurotrophic factor (BDNF), calcium channel, voltage dependent P/Q type, catechol-O-methyltransferase (COMT), dopamine receptor D2 and ankyrin repeat and kinase domain containing 1 (DRD2 and ANKK1), interleukin-1 (IL-1), interleukin-6 (IL-6), kidney and brain expressed protein (KIBRA), neurofilament, heavy polypeptide (NEFH), endothelial nitric oxide synthase 3 (NOS3), poly (ADP-ribose) polymerase-1 (PARP-1), protein phosphatase 3, catalytic subunit, gamma isozyme (PPP3CC), the serotonin transporter (5-HTT) gene solute carrier family 6 member (SLC6A4) and tumor protein 53 (TP53). It is evident that contradicting results are attributable to the heterogeneity of studies, thus further researches are warranted to effectively assess a relation between genetic traits and clinical outcome following traumatic injuries.