AIM: To evaluate the interaction effects of season of birth and immune system genes on the personality traits 'Novelty seeking' (NS) and 'Self-directedness' (SD). Based on results on an influence of the immune system on the brain processes, the authors hypothesized that the interaction of immune system genes and season of birth, which is relevant for immune phenotype, can contribute to the development of personality traits. MATERIAL AND METHODS: NS and SD were measured in 336 healthy volunteers, aged from 16 to 67 years, using the Temperament and Character Inventory (TCI-125). IL1B C3954T, IL4 C-589T, IL13 C1112T and TNFA G-308A polymorphisms were genotyped. RESULTS: An interaction effect of IL4 C-589T and season of birth on the personality traits was found (F2,322=6.03, pcorr=0.011, η2=0.04). Carriers of the minor allele T, who were born in winter, had lower NS and higher SD. There was a nominal main effect of genotype on SD (F=5.44, p=0.020) as well, with higher SD scores in carriers of the allele T compared to the CC genotype. CONCLUSION: The results suggest that the etiology of personality and immune characteristics can share common genetic elements including IL-4.
Character , Cytokines/genetics , Exploratory Behavior , Immunity/genetics , Parturition , Personal Autonomy , Temperament , Adolescent , Adult , Aged , Alleles , Brain/physiology , Female , Genotype , Humans , Middle Aged , Polymorphism, Genetic , Pregnancy , Seasons , Young Adult
Associations between schizotypal traits and genes coding for inflammation markers (Creactive protein and TNF-α) were studied in 222 healthy men who completed the Schizotypal Personality Questionnaire (SPQ-74). CRP -717A>G and TNFα -308 G>A polymorphisms were genotyped. Carriers of low-active allele G of the CRP gene differed from subjects with genotype AA by a trend toward more manifest schizotypal traits in general and scores on the Interpersonal factor, which corresponds to negative syndrome in schizophrenia, and Constricted affect and Odd behavior scales. These results could be interpreted in favor of the hypothesis on a compensatory increase of CRP concentrations in subjects with abnormalities of CNS development that predispose to schizophrenia.
Alleles , C-Reactive Protein/genetics , Polymorphism, Single Nucleotide , Schizotypal Personality Disorder/genetics , Tumor Necrosis Factor-alpha/genetics , Adolescent , Adult , Biomarkers/metabolism , C-Reactive Protein/immunology , Gene Expression , Gene Frequency , Genotype , Humans , Male , Middle Aged , Phenotype , Promoter Regions, Genetic , Schizotypal Personality Disorder/diagnosis , Schizotypal Personality Disorder/immunology , Schizotypal Personality Disorder/psychology , Surveys and Questionnaires , Tumor Necrosis Factor-alpha/immunology
Neurotoxic products produced during tryptophan metabolism via the kynurenine pathway could be involved in schizophrenia pathogenesis. It has been shown that kynurenine-3-monooxygenase (KMO) is indirectly involved in these products' formation. KMO polymorphic loci rs2275163 (C/T) and rs1053230 (A/G) were examined in 187 schizophrenia patients and 229 healthy subjects. A genetic combination of allele T and genotype GG was observed more often in a patient group compared with healthy controls (p = 0.003, OR 2.0 (95% CI 1.2-2.9). In the latter group, this combination was associated with schizophrenia endophenotype (p = 0.04), which manifested in a higher expression of schizotypal personality traits assessed using the MMPI test.
Kynurenine 3-Monooxygenase/genetics , Polymorphism, Single Nucleotide , Schizophrenia/genetics , Adolescent , Adult , Case-Control Studies , Female , Humans , Male
