Table 1.

Summary of polymorphisms examined in this study.

Gene Name	Gene Abbreviation and Polymorphism Identifier	Alleles	Relevant Effects Associated with TBI
Ankyrin repeat and kinase domain containing 1	ANKK1 rs1800497	A/G	The A allele has been associated with altered cognitive behavioural capacity via modulation of expression of D2 receptors.
Apolipoprotein E	APOE rs429358, rs7412	ε2, ε3, ε4	Affects repair and plasticity of the brain. APOE isoforms have differing effects on neurite extension, which can influence ability to recover post-concussion.
	rs405509	G/T	Associated with functional regulation of APOE transcription.
Brain-derived neurotrophic factor	BDNF rs6265	Val/Met (C/T)	Affects repair and plasticity of the brain via strengthening existing synaptic connections and modulating the creation of new synapses.
Catechol-O-methyltransferase	COMT rs4680	Met/ Val (A/G)	Affects cognitive behavioural capacity post-concussion and could increase impulsivity and risk taking.
Microtubule-associated protein tau	MAPT rs10445337	C/T	Affects repair and plasticity of the brain via modulation of microtubule formation, structural stabilisation of the neuronal axons and drives growth of neurites.
Endothelial nitric oxide synthase	NOS3 rs2070744	C/T	Could affect severity of concussion and cognitive behavioural capacity post-concussion via modulating cerebral blood.

Alleles previously associated with traumatic brain injury are underlined (adapted from Antrobus et al. [14]).