Variations within the serotonin transporter gene, SLC6A4 (solute carrier family 6 member 4), particularly the 5-HTTLPR (serotonin-transporter-linked promoter region), have been extensively studied in relation to behavioral and psychological traits. The aim of our study is to examine the relationship between the 5-HTTLPR polymorphism located in the SLC6A4 gene and personality traits, as assessed using the NEO-FFI (NEO Five Factor Inventory). The MANOVA model demonstrated a significant overall association, accounting for approximately 8% of the variance in the data (Wilk’s λ = 0.847, F_10,342 = 2.979, p = 0.0013, η² = 0.08). Subsequent ANOVAs revealed statistically significant 5-HTTLPR polymorphism associations with the Neuroticism (p = 0.0018, R² = 0.070), Openness (p = 0.0364, R² = 0.037), and Conscientiousness (p = 0.0020, R² = 0.068) dimensions. The post-hoc analysis revealed that individuals with the LL genotype obtained significantly lower Neuroticism scores compared to the S/S (p = 0.0011) and SL genotype (p = 0.0086) carriers. Similarly, individuals with the L/L genotype had lower Openness scores compared to those with SS genotype (p = 0.0107). LL and SL genotype carriers had higher Conscientiousness scores compared to those with the SS genotype (p = 0.0004 and p = 0.0109, respectively). In conclusion, our study provides further data regarding the implications of 5-HTTLPR polymorphism in the complex genetic architecture of human personality. The observed associations with Neuroticism, Openness, and Conscientiousness, while modest in effect size, contribute to our understanding of how genetic variation at the SLC6A4 locus may subtly shape individual personality differences.

Background/Objectives: Left ventricular hypertrophy is a significant independent risk factor for increased cardiovascular morbidity and mortality. There are some reports indicating an association of rs1403543 (1675G>A) polymorphism in the AGTR2 gene, which encodes the type-2 angiotensin II receptor, with left ventricular hypertrophy or increased left ventricular mass (LVM) in adults. The aim of this study was to analyze the possible association of the AGTR2:rs1403543 polymorphism with LVM in full-term Polish healthy newborns. Methods: The study group comprised 207 consecutive, full-term, healthy newborns. LVM was assessed, on the 3rd day after birth, from the M-mode echocardiographic measurements of left ventricular dimensions using the Penn convention, with the Huwez et al.-modified equation mode. The AGTR2 polymorphism was identified by PCR-RFLP in genomic DNA extracted from cord blood leukocytes. Results: There were no significant differences in clinical and echocardiographic characteristics of male newborns in regard to the AGTR2:rs1403543 polymorphism. However, the LVM/body mass ratio in female newborns carrying at least one A allele (i.e., with genotype GA or AA) was significantly lower as compared to its value in reference (GG) homozygotes. In addition, in female newborns, the frequency of AGTR2 genotypes with at least one A allele was significantly higher in the lower tertile of LVM/body mass or LVM/body surface area (calculated using the Mosteller formula) ratios as compared with upper tertiles. Conclusions: Our results suggest that the AGTR2:rs1403543 polymorphism may be associated with the physiological variability of cardiac mass in female newborns.

The dysregulation of the serotonin system has been implicated in the pathophysiology of alcohol use disorders. Meta-analytic evidence suggests a significant correlation between genetic variation in the serotonin transporter gene and the risk of alcohol dependence. Hence, we aimed to analyse the association between 5-HTTLPR polymorphism and alcohol use disorder in a group of women and to perform an interaction analysis of 5-HTTLPR variants, personality traits, and AUD. The study group comprised 213 female volunteers; 101 were diagnosed with alcohol addiction, and 112 were not dependent on any substance or behaviour. The 5-HTTLPR variants were identified by PCR, and the resulting products were separated electrophoretically. When comparing the AUD group with the controls, we observed significant differences in the distribution of 5-HTTLPR genotypes (p = 0.0230) and alleles (p = 0.0046). We also observed a significant impact of the 5-HTTLPR genotype (p = 0.0001) on the Neuroticism and Extraversion (p = 0.0037) scales. Additionally, there was a statistically significant impact of 5-HTTLPR genotype interaction and alcohol dependency or lack of it on the Neuroticism scale (p < 0.0001). The observed interaction suggests that the effect of the 5-HTTLPR on neuroticism may be exacerbated or attenuated in the presence of alcohol addiction. Further investigation is needed to elucidate the precise nature of this interaction. Still, it potentially indicates a gene–environment interaction where the genetic predisposition conferred by the 5-HTTLPR polymorphism interacts with the environmental stressor of alcohol dependence to influence neuroticism.

Background: The correlation between renal volume (or mass) and nephron number in newborns allows the use of the total kidney volume (TKV) at birth as a surrogate for congenital nephron number. Previously, the wide variation in final nephron number (termed “nephron endowment”) has been attributed to polymorphisms of genes encoding proteins involved in glomerulogenesis, including key genetic variants in the renin–angiotensin system. However, there are no data concerning the role of polymorphism in the gene encoding type-2 angiotensin II receptor (AGTR2) in the modulation of nephron endowment in humans. Therefore, the aim of our study was to analyze the possible association between AGTR2:rs1403543 polymorphism and kidney volume in Polish full-term healthy newborns. Methods: The study group consisted of 208 healthy, Polish, full-term newborns born to healthy women with uncomplicated pregnancies. The AGTR2:rs1403543 polymorphism was identified by PCR-RFLP in genomic DNA extracted from cord blood leukocytes. Kidney volume was measured sonographically. Total kidney volume was calculated as the sum of left and right kidneys, and normalized for body mass (BM), body length (BL), or body surface area (BSA). Results: There were no significant differences in TKV/BM, TKV/BL, or TKV/BSA between male and female newborns, as well as in regard to the AGTR2:rs1403543 polymorphism. Conclusions: The results suggest a lack of association between the AGTR2:rs1403543 polymorphism and physiological variability in kidney volume in full-term newborns.