{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T20:03:52Z","timestamp":1789243432933,"version":"build-2803163510"},"reference-count":43,"publisher":"BMJ","issue":"1","funder":[{"name":"South African National Research Foundation","award":["85534"],"award-info":[{"award-number":["85534"]}]},{"name":"South African National Research Foundation","award":["90942"],"award-info":[{"award-number":["90942"]}]},{"name":"South African National Research Foundation","award":["93416"],"award-info":[{"award-number":["93416"]}]},{"DOI":"10.13039\/501100007112","name":"University of Cape Town","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100007112","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Deutscher Akademischer Austauschdienst"}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open Sport Exerc Med"],"accepted":{"date-parts":[[2018,12,8]]},"published-print":{"date-parts":[[2019,2]]},"abstract":"<jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Concussion occurs when biomechanical forces transmitted to the head result in neurological deficits. Personality may affect the balance between safe and dangerous play potentially influencing concussion risk. Dopamine receptor D2 (<jats:italic>DRD2<\/jats:italic>) and dopamine receptor D4 (<jats:italic>DRD4<\/jats:italic>) genetic polymorphisms were previously associated with personality traits.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Objectives<\/jats:title>\n                  <jats:p>This case\u2013control genetic association study investigated the associations of (1) <jats:italic>DRD2<\/jats:italic> and <jats:italic>DRD4<\/jats:italic> genotypes with concussion susceptibility and personality, (2) personality with concussion susceptibility and (3) the statistical model of genotype, personality and concussion susceptibility.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>In total, 138 non-concussed controls and 163 previously concussed cases were recruited from high school (n=135, junior), club and professional rugby teams (n=166, senior). Participants were genotyped for <jats:italic>DRD2<\/jats:italic> rs12364283 (A&gt;G), <jats:italic>DRD2<\/jats:italic> rs1076560 (C&gt;A) and <jats:italic>DRD4<\/jats:italic> rs1800955 (T&gt;C) genetic variants. Statistical analyses including structural equation modelling were performed using the R environment and STATA.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>The rs1800955 CC genotype (p=0.014) and inferred <jats:italic>DRD2<\/jats:italic> (rs12364283\u2013rs1076560)<jats:italic>\u2013DRD4<\/jats:italic> (rs1800955) A\u2013C\u2013C allele combination (p=0.019) were associated with decreased concussion susceptibility in juniors. The rs1800955 TT and CT genotypes were associated with low reward dependence in juniors (p&lt;0.001) and seniors (p=0.010), respectively. High harm avoidance was associated with decreased concussion susceptibility in juniors (p=0.009) and increased susceptibility in seniors (p=0.001). The model showed that a genetic variant was associated with personality while personality was associated with concussion susceptibility.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusion<\/jats:title>\n                  <jats:p>These findings highlight the linear relationship between genetics, personality and concussion susceptibility. Identifying a genetic profile of \u2018high risk\u2019 behaviour, together with the development of personalised behavioural training, can potentially reduce concussion risk.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/bmjsem-2018-000465","type":"journal-article","created":{"date-parts":[[2019,2,2]],"date-time":"2019-02-02T12:35:13Z","timestamp":1549110913000},"page":"e000465","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":20,"title":["Unravelling the interaction between the <i>DRD2<\/i> and <i>DRD4<\/i> genes, personality traits and concussion risk"],"prefix":"10.1136","volume":"5","author":[{"given":"Shameemah","family":"Abrahams","sequence":"first","affiliation":[{"name":"Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Science, University of Cape Town, Cape Town, South Africa"},{"name":"Division of Molecular Biology and Human Genetics, Faculty of Medicine and 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