Genetic Polymorphisms Influence Recovery from Traumatic Brain Injury

Abstract

Traumatic brain injury (TBI) is a major public health concern in both civilian and military populations. Recently, genetics studies have begun to identify individual differences in polymorphisms that could affect recovery and outcome of cognitive and social processes following TBI. This review considers the potential for polymorphisms to influence six specific cognitive and social functions, which represent the most prominent domains of impairment following TBI: working memory, executive function, decision making, inhibition and impulsivity, aggression, and social and emotional function. Examining the influence of polymorphisms on TBI outcome has the potential to contribute to an understanding of variations in TBI outcome, aid in the triaging and treatment of TBI patients, and ultimately lead to targeted interventions based on genetic profiles.

COMTVal158Metand Cognitive and Functional Outcomes after Traumatic Brain Injury

“…1 Thus, examination of just one of these alleles in isolation (candidate gene approach) does not allow for any underlying relationships between SNPs and genes to be studied and does not take into account environmental modifications of gene expression. 2 A number of recent reviews 6,65 and studies investigating influence of other polymorphisms on outcome after TBI 66 have advocated for the examination of the interactions between a range of candidate alleles likely to contribute to cognition. Full screening of the COMT gene and other dopaminergic genes, such as dopamine receptor D2 gene or ankyrin repeat and kinase domain-containing 1, which are known to be associated with cognition, is recommended.…”

“…Full screening of the COMT gene and other dopaminergic genes, such as dopamine receptor D2 gene or ankyrin repeat and kinase domain-containing 1, which are known to be associated with cognition, is recommended. 65 Whether studying the influence of a single gene, interaction between a range of candidate alleles or multiple genes, or taking a genome-wide approach, it is clear that very large samples are required to confer sufficient statistical power to detect effects. This would perhaps be best facilitated by large-scale collaborative, multi-institutional studies.…”

“…10 Thus, individuals homozygous for the Val form metabolize catecholamines more rapidly than those with the Met form, resulting in 1 School of Psychological Sciences, Monash University, Clayton, VIC, Australia. 2 Monash-Epworth Rehabilitation Research Center, Richmond, VIC, Australia. 3 School of Biological Sciences, Monash University, Clayton, VIC, Australia.…”

“…These deficits have been found to predict long-term functional outcomes. 2 Despite characteristic patterns of impairment, there remains substantial variability in outcomes across individuals, even within injury severity categories after TBI. This makes accurate clinical prognosis difficult in individual cases.…”

The Influence ofBMXGene Polymorphisms on Clinical Symptoms after Mild Traumatic Brain Injury

“…Genetic variations of the apolipoprotein E ( APOE ) gene have been demonstrated to be associated with long-term functional outcome after TBI [9–11]. Polymorphisms of brain-derived neurotrophic factor ( BDNF ), monoamine oxidase A ( MAO-A ), and interleukin-6 (IL-6) have also been correlated with TBI in recent studies [12–14]. Results of these studies identified several candidate genes associated with TBI, but these results are still controversial and need further validation.…”