Allele polymorphism of the serotonin transporter gene and clinical heterogeneity of depressive disorders

Depression disorders are a clinically heterogeneous disease group. Their development is to a substantial extent underlain by dysfunction of the serotonin system, in particular, disturbed serotonin transport. The heterogeneity of depressions is associated, among other factors, with the age at disease onset. Allele polymorphism of the serotonin transporter (5-HTT) gene was tested for association with age at disease onset, clinical signs, and anxiety-related traits of depression patients. A sample included 77 patients (mean age 61.2 +/- 8.8 years) with late-onset depression (LOD, mean age at onset 56.58 +/- 9.7 years) and 74 patients (mean age 31.0 +/- 11.8 years) with early-onset depression (EOD, mean age at onset 23.9 +/- 7.4 years). In genotype frequency distribution of two 5-HTT gene polymorphism, the LOD and EOD groups did not differ from each other (chi 2 = 0.33, P = 0.85 for VNTR-17; chi 2 = 3.33, P = 0.19 for HTTLPR) and from a control group (chi 2 = 0.34, P = 0.84 for VNTR-17; chi 2 = 2.1, P = 0.35 for HTTLPR). In either group, patients differing in VNTR-17 and HTTLPR genotypes did not differ in psychological traits and, in particular, in anxiety-related traits. In the case of the HTTLPR polymorphism, LOD patients with genotype ss tended to display less severe neuroticism (t = 2.03, P = 0.0507) and scored significantly less on the Hamilton depression scale (t = 2.19, P = 0.039). Thus, the 5-HTT gene polymorphisms do not affect the risk of depression but is possibly associated with specific clinical signs of the disease, at least in elderly patients.     

Insertion/Deletion Polymorphism of the Serotonin Transporter Gene and Neuroticism as a Temperament Trait in Affective Patients and Healthy Individuals

Some studies associate the insertion/deletion polymorphism of the serotonin transporter (5-HTT) gene with anxiety-related personality traits in mentally healthy people, the short (s) allele being associated with a higher neuroticism score. The 5-HTT genotype and neuroticism score were established for 114 affective patients, 87 healthy relatives of endogenous psychosis patients, and for 156 mentally healthy people without familial psychiatric history. The effects of sex and age on the association between the two parameters was studied. Neuroticism proved to be not associated with the 5-HTT genotype.     

Glutathione system of erythrocyte and plasma in peptic ulcer

A complex study of the blood glutathione system has been carried out for the first time in patients with peptic (gastric and duodenal) ulcer. In erythrocytes and blood plasma of patients with the complicated peptic ulcer and postgastroresection syndromes there was the increase of conjugated dienes (and in the second group the increase in antioxidant activity). Under these conditions the main change was the sharp and identical decrease in glutathione peroxidase activity. In patients with uncomplicated peptic ulcer there was sharp increase in erythrocite and plasma glutathione reductase activity and plasma GSH. In operated but basically healthy patients plasma glutathione peroxidase remained decreased but plasma GSH sharply increased. Evidently complicated peptic ulcer is characterized by decreased functioning of the glutathione system. Activation of this system and the decrease or disappearance of manifestations of oxidative stress are associated with a favorable course of this disease, especially at uncomplicated peptic ulcer. The revealed changes significantly differ from those observed in patients with viral hepatitis, blle excretory diseases and strokes.     

Self-regulation of autonomic homeostasis in emotional stress

Emotional stress is considered to be one of the basic pathogenetic factors causing diseases of the cardiovascular system [1]. Its particular example is the examination stress, which develops in some students expecting an examination. In this case the reactions of the autonomic system in some persons can be oppositely directed and reach a magnitude that puts an organism on the borderline between norm and pathology [2]. There-fore, the qualitative and quantitative estimation of the character of the reaction of the autonomic system to stress in students and the development of the methods of its correction are relevant.     

Genetic association between the apolipoprotein E (ApoE) gene alleles and various forms of Alzheimer's disease]

Allele epsilon 4 of the apolipoprotein E (APOE) gene is associated with higher risk of Alzheimer's disease (AD) in many, though not all, ethnic groups. The APOE allele and genotype frequency distributions were studied in 207 AD patients without cerebrovascular disorders, 62 AD patients with cerebrovascular disorders (combined AD), and 206 control individuals (ethnic Russians from the Russian population). The frequency of allele epsilon 4 in patients with early-onset and late-onset AD was three times higher than in control individuals (p < 0.000001). Compared with control people, patients with cerebrovascular disorders displayed a twofold higher frequency of allele epsilon 4; the difference between the two groups was significant (p = 0.0019). Relative risk of AD in carriers of allele epsilon 4 was five times higher than in carriers of alleles epsilon 2 and epsilon 3 (p < 0.000001). Allele epsilon 2 had a protective effect with respect to AD onset until 65 years of age (p = 0.015). Thus, APOE allele epsilon 4 proved to be a universal factor of early-onset, late-onset, and combined AD in ethnic Russians from Russia.     

Gene insertion and deletion polymorphism in the serotonin transporter gene and personality traits measured by MMPI

Polymorphisms of the serotonin transporter gene are known to be associated with some personality traits measured by means of various psychological inventories. In the present work we attempted to find an association between genetic variants of serotonin transporter (loci VNTR-17 and 5-HTTLPR) and psychological traits scored by the MMPI inventory in 125 mentally healthy donors. No statistically significant differences in personality traits were found between carriers of different VNTR-17 genotypes. At locus 5-HTTLPR, significant between-genotype differences were revealed on the Schizophrenia scale (F = 3.49; P = 0.034) and on the validity scale F (F = 3.24; P = 0.042). The ss genotype carriers had the lowest scores on these scales. The score on the Psychopathic Deviate scale was significantly lower in the carriers of the ss genotype than in the combined group of the carriers of genotypes ll and ls (t = 2.07; P = 0.041). The differences on the validity scale K between the carriers of the ll and ss genotypes were also statistically significant (t = 2.49; P = 0.015). These results suggest that polymorphism of the serotonin transporter gene may be associated with the expression of schizoid traits (namely, social introversion, internal tension, weird thoughts and actions) in mentally healthy individuals. In the context of social adaptation, the personality profile configuration and data of statistical analysis indicate that the carriers of the ss genotype are more inclined to observe social norms than the carriers of the ll and ls genotypes.     

Effects of parameters of the higher nervous activity on stress in students during exams

The complex research of visceral responses of the students in conditions of examination stress was conducted. The main parameters of hemodynamic and heart rate variability were investigated depending on a type of higher nervous activity and self-evaluation of the students. It is shown, that at the students with a high level of steadiness of nervous processes at examination the increased vagal activity is marked, and in the students with a high level of self-evaluation at examination the lower activation of a sympathetic system is revealed.     

Polymorphism in the human serotonin transporter gene in endogenous psychoses

Associations of the VNTR-17 and 5-HTTLPR polymorphisms of the serotonin transporter gene with affective disorders, including depression, have been found. These polymorphisms were analyzed in two groups of Russian probands: patients with endogenous psychoses and control individuals without mental disorders (423 and 277 persons, respectively). No associations were found between VNTR-17 genotypes or alleles and the diseases. However, the frequency of 10/10 (VNTR-17) homozygotes increased with age in both patients and healthy persons. The results of the analysis of the 5-HTTLPR polymorphism suggest an association of the short (s) allele of the 5-HTTLPR polymorphism with schizophrenia and schizoaffective psychoses, but not with affective disorders.