Problems with working memory, executive function, decision-making, inhibition, impulsivity, aggression, and social or emotional function are common after a traumatic brain injury. Although these skills and traits can vary considerably by the severity of injury, as well as variances in medical and social support, they are also influenced by genetics.
Scientists have isolated the specific genes that influence cognition and behaviors. These genes can act in unison to broadly affect a behavior, or they can target a single neurotransmitter or hormone that influences either the whole brain, or specific areas. Polymorphisms, which are variations of more than one associated gene, have the greatest influence on outcome after a brain injury.
A person's genetic makeup is highly individual, and may only predispose a person to certain behaviors. The presence or absence of a specific gene may be devastating to outcome, or have no effect at all. However, when a potential outcome of a brain injury is uncertain, the identification of polymorphisms may be a helpful aid at both triage and in choosing interventions.
Weaver SM, Chau A, Portelli JN, & Grafman J. Genetic polymorphisms influence recovery from traumatic brain injury. The Neuroscientist. (March 2012).