title: Genetic variability in glutamic acid decarboxylase genes: associations with post-traumatic seizures after severe TBI.
abstract: Post traumatic seizures (PTS) occur frequently after traumatic brain injury (TBI). Since gamma-amino butyric acid (GABA) neurotransmission is central to excitotoxicity and seizure development across multiple models, we investigated how genetic variability for glutamic acid decarboxylase (GAD) influences risk for PTS. Using both a tagging and functional single nucleotide polymorphism (SNP) approach, we genotyped the GAD1 and GAD2 genes and linked them with PTS data, regarding time to first seizure, obtained for 257 adult subjects with severe TBI. No significant associations were found for GAD2. In the GAD1 gene, the tagging SNP (tSNP) rs3828275 was associated with an increased risk for PTS occurring <1 wk. The tSNP rs769391 and the functional SNP rs3791878 in the GAD1 gene were associated with increased PTS risk occurring 1 wk-6 mo post-injury. Both risk variants conferred an increased susceptibility to PTS compared to subjects with 0-1 risk variant. Also, those with haplotypes having both risk variants had a higher PTS risk 1 wk-6 mo post-injury than those without these haplotypes. Similarly, diplotype analysis showed those with 2 copies of the haplotype containing both risk alleles were at the highest PTS risk. These results implicate genetic variability within the GABA system in modulating the development of PTS.
authors: University of Pittsburgh, Department of Physical Medicine & Rehabilitation, 3471 Fifth Avenue, Suite 202, Pittsburgh, PA 15213, United States. Darrah.shaun@medstudent.pitt.edu
authors: Shaun D
authors: SD
authors: Darrah
authors: Megan A
authors: MA
authors: Miller
authors: Dianxu
authors: D
authors: Ren
authors: Nichole Z
authors: NZ
authors: Hoh
authors: Joelle M
authors: JM
authors: Scanlon
authors: Yvette P
authors: YP
authors: Conley
authors: Amy K
authors: AK
authors: Wagner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000201:enzymology / Q000453:epidemiology* / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation / Q000235:genetics; D005968:Glutamate Decarboxylase / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012640:Seizures / Q000201:enzymology / Q000453:epidemiology* / Q000235:genetics*; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; C401141:glutamate decarboxylase 2