Interactions between functional serotonergic polymorphisms and demographic factors influence personality traits in healthy Spanish Caucasians.
BACKGROUND
Data from epidemiological genetic studies suggest that variability in personality traits is explained, at least partly, by genetic factors. Recently, a growing number of molecular genetic studies have suggested the involvement of the serotonin system in specific traits.


OBJECTIVE
To investigate the association between three serotonergic polymorphisms [A-1438G (rs6311) of the HTR2A gene, and STin2 VNTR and 5-HTTLPR of the SLC6A4 gene] and personality traits assessed with the Temperament and Character Inventory.


METHODS
Four hundred and four unrelated healthy volunteers [50% males, mean age (standard deviation)=40.5 (11.3)] from Asturias (northern Spain) were genotyped using standard methods. Cloninger's Temperament and Character Inventory was used for investigation of temperament and character traits.


RESULTS
The genetic variants were in Hardy-Weinberg equilibrium and genotypic frequencies were similar in both the sexes. 5-HTTLPR was associated with a direct effect on self directedness (F=6.20, P=0.002), and interacting with educational level (F=3.10, P=0.016) and A-1438G (F=3.34, P=0.011) with respect to novelty seeking. STin2 VNTR interacted with age in relation to reward dependence (F=2.74, P=0.013) and with sex in relation to cooperation (F=5.10, P=0.007). In addition, SLC6A4 haplotypes had significant effects on harm avoidance (lower in volunteers with L12), self directedness (higher in volunteers with L12), and self transcendence (higher in volunteers with S10).


CONCLUSIONS
Our findings suggest a strong genetic component in personality traits manifested primarily through interaction effects that occur between genetic factors alone and between genetic and demographic factors.
Saiz
Pilar Alejandra
PA
Department of Psychiatry, School of Medicine, University of Oviedo, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Julian Claveria, Spain. frank@uniovi.es
Garcia-Portilla
Maria P
MP
Herrero
Rocío
R
Arango
Celso
C
Corcoran
Paul
P
Morales
Blanca
B
Bascarán
Maria-Teresa
MT
Alvarez
Victoria
V
Coto
Eliecer
E
Paredes
Begoña
B
Fernández
Juan M
JM
Bobes
Julio
J
D000328:Adult; D001362:Avoidance Learning; D003299:Cooperative Behavior; D003710:Demography; D005106:Exploratory Behavior; D005260:Female; D006239:Haplotypes / Q000235:genetics; D006262:Health; D006801:Humans; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics; D009042:Motivation / Q000235:genetics; D010551:Personality / Q000235:genetics*; D011110:Polymorphism, Genetic; D019655:Quantitative Trait, Heritable; D012201:Reward; D012701:Serotonin / Q000235:genetics*; D013030:Spain; D013694:Temperament; D044465:White People / Q000235:genetics*; D055815:Young Adult
D012701:Serotonin