Impact of P2RX7 and TNF/LTA gene polymorphisms in nonverbal intelligence in mentally healthy individuals

by Enikeeva R. | Kazantseva A. | Davydova Yu. | Mustafin R. | Malykh S. | Lobaskova M. | Takhirova Z. |
Abushakhmina A. | Khusnutdinova E. | Institute of Biochemistry and Genetics –
Subdivision of the Ufa Federal Research Centre of the Russian Academy of Sciences | Bashkir State Medical University | Psychological Institute of Russian Academy of Education 

Motivation and Aim: Nonverbal intelligence as one of cognitive abilities implies an
individual’s ability to use problem-solving strategies and manipulate visual information
without using verbal skills. In this regard, the purpose of this work was to study the SNPs of
genes involved in regulation of inflammatory mediators (TNF/LTA rs1041981, rs1800629,
and P2RX7 rs2230912) and their role in the formation of individual differences in the level
of nonverbal intelligence in mentally healthy individuals.
Methods and Algorithms: The study involved 1011 mentally healthy individuals (Russians,
Tatars and Udmurts) from Republic of Bashkortostan (80% women) (mean age 19,79±1,69
years). SNPs genotyping was performed via real-time PCR with a fluorescent detection
using the KASP method. Detection was carried out on the CFX96 DNA Analyzer (Bio-Rad,
USA) with the endpoint fluorescence analysis. The level of nonverbal intelligence was
measured using a black-and-white version of the Raven Progressive Matrices. Statistical
analysis was conducted with Plink v.1.09.
Results: As a result of haplotypic analysis we detected the association of the TNF/LTA*АА
haplotype (rs1041981, rs1800629) (βST = 1.19; p = 0.033; pperm = 0.047) with an enhanced
level of nonverbal intelligence in individuals without cognitive decline. In the present study
we also conducted the analysis of gene-by-environment (G×E) interactions estimating the
effect of 14 socio-demographic parameters. As a result of G×E interactions we observed
that sibship size significantly affected the association of the rs1041981 in the TNF/LTA gene
(β = 2.08; βST = 0.16; p = 0.001) and a dose-dependent effect of P2RX7 rs2230912 minor Gallele on a decreased level of nonverbal intelligence among smoking individuals (β = –1.70;
βST = –0.10; р = 0.022).
Conclusion: The results obtained within the framework of this study confirm the role of the
inflammatory mediator’s system in the formation of differences in the level of nonverbal
intelligence in mentally healthy individuals.

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