Association between GRIN2A promoter polymorphism and recovery from concussion.
OBJECTIVE
To determine genetic variability within the N-methyl-D-aspartate receptor 2A sub-unit (GRIN2A) gene promoter and its association with concussion recovery time. The hypothesis tested was that there would be a difference in allele and/or genotype distribution between two groups of athletes with normal and prolonged recovery.


METHODS
DNA was extracted from saliva collected from a total of 87 athletes with a physician-diagnosed concussion. The (GT) variable number tandem repeats (VNTR) within the promoter region of GRIN2A was genotyped. The long (L) allele was an allele with ≥25 repeats and the short (S) allele was an allele with <25 repeats in the GT tract. Participants' recovery time was followed prospectively and was categorized as normal (≤60 days) or prolonged (>60 days).


RESULTS
LL carriers were 6-times more likely to recover longer than 60 days following the concussive event (p = 0.0433) when compared to SS carriers. Additionally, L allele carriers were found more frequently in the prolonged recovery group (p = 0.048).


CONCLUSIONS
Determining genetic influence on concussion recovery will aid in future development of genetic counselling. The clinical relevance of genotyping athletes could improve management of athletes who experience concussion injuries.
a Department of Kinesiology , Temple University , Philadelphia , PA , USA .
Jane
J
McDevitt
a Department of Kinesiology , Temple University , Philadelphia , PA , USA .
Ryan Timothy
RT
Tierney
a Department of Kinesiology , Temple University , Philadelphia , PA , USA .
Jacqueline
J
Phillips
b Biostatistics Consulting Center , Philadelphia , PA , USA .
John P
JP
Gaughan
c Department of Orthopedic Surgery , Temple University School of Medicine , Philadelphia , PA , USA , and.
Joseph S
JS
Torg
d Temple University School of Pharmacy , Philadelphia , PA , USA.
Evgeny
E
Krynetskiy
D000293:Adolescent; D000328:Adult; D000483:Alleles; D056352:Athletes; D001924:Brain Concussion / Q000175:diagnosis / Q000235:genetics* / Q000534:rehabilitation*; D016022:Case-Control Studies; D004247:DNA / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D008297:Male; D018598:Minisatellite Repeats; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics*; D020127:Recovery of Function; D012463:Saliva / Q000737:chemistry; D016896:Treatment Outcome; D055815:Young Adult
D004247:DNA; D016194:Receptors, N-Methyl-D-Aspartate
Brain injury; NR2A sub-unit; calcium