Association of KIBRA rs17070145 polymorphism and episodic memory in individuals with severe TBI.
BACKGROUND
Studies implicate single nucleotide polymorphism (SNP) rs17070145, a common T → C polymorphism on the KIBRA gene, in mediating differences in episodic memory. In healthy adults, T-allele carriers perform better than non-carriers on episodic memory measures. However, this association is reversed in adults with subjective memory complaints and populations vulnerable to memory deficits, a problem common in traumatic brain injury (TBI).


METHODS
This study assessed associations between variation in the KIBRA gene and cognitive function in 129 adults with severe TBI. In addition to other executive functioning and functional/global outcomes, the Buschke Selective Reminding Test (SRT), Rey-Osterrieth Complex Figure Test and California Verbal Learning Test-II (CVLT-II) were administered 6 and 12 months post-injury.


RESULTS
T-allele non-carriers performed better than carriers on multiple episodic memory measures. At 6 months, T-allele non-carriers performed better for delayed recall measures on the SRT. At 12 months, T-allele non-carriers performed better on multiple SRT measures and on List-B learning with CVLT-II. No associations occurred with executive function or global outcome measures.


CONCLUSIONS
These results suggest that rs17070145 T-allele effects are specific to episodic memory and support the hypothesis that associations between rs17070145 variation and memory are disparate between healthy and impaired populations.
Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, USA. wagnerak@upmc.edu
Amy K
AK
Wagner
Laura E
LE
Hatz
Joelle M
JM
Scanlon
Christian
C
Niyonkuru
Megan A
MA
Miller
Joseph H
JH
Ricker
Yvette P
YP
Conley
Robert E
RE
Ferrell
D000293:Adolescent; D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000523:psychology*; D003071:Cognition; D003072:Cognition Disorders / Q000209:etiology* / Q000235:genetics / Q000523:psychology; D005260:Female; D005838:Genotype; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged; D009483:Neuropsychological Tests; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult
D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; C513637:WWC1 protein, human