Hüseyin Güleç

Association Between Polymorphisms of DNA Repair Genes and Risk of Schizophrenia

AIMS DNA repair gene polymorphisms have recently been implicated as potential pathogenic contributors of mental disorders. The aims of our study were to investigate the participation of nucleotide and base excision repair mechanisms in schizophrenia and to identify novel candidate DNA repair susceptibility genes. MATERIALS AND METHODS For these purposes, we genotyped apurinic/apyrimidinic endonuclease 1 (APE1), human 8-oxoguanine DNA N-glycosylase 1 (hOGG1), X-ray repair cross-complementation group 1 (XRCC1), XRCC3, xeroderma pigmentosum group D (XPD), and xeroderma pigmentosum group G (XPG) genes in schizophrenia subjects, their healthy relatives, and unrelated healthy controls. RESULTS Carriers of XRCC1 glutamine (Gln), XRCC3 threonine (Thr), hOGG1 cysteine (Cys), and XPD lysine (Lys) alleles were significantly more frequent among the cohort of schizophrenia patients than in controls. In contrast, the frequencies of XRCC3 methionine (Met) and XPD Gln allele carriers and hOGG1 serine (Ser)/Ser genotype carriers were higher among controls than in patients, suggesting a possible protective role for these gene variants against schizophrenia. Moreover, healthy relatives had significantly higher frequencies of XRCC3 Thr+ and XPD Lys+ genotypes than unrelated healthy controls. Minor allele frequencies, haplotypes, and overtransmitted alleles of DNA repair genes were also identified. CONCLUSION Our findings support XRCC1, XRCC3, hOGG1, and XPD as risk genes for schizophrenia and suggest that altered DNA repair functions may be involved in schizophrenia pathophysiology.

Effects of personality functioning on the global functioning of patients with bipolar disorder I

Due to the comorbidity of personality traits or disorders and BD, the present study investigated the extent to which the global functioning of patients with BD would be affected by personality functioning. This study included 100 subsequent patients who had been diagnosed with BD-I, and were in the remission phase. Global functioning was assessed with the Bipolar Disorder Functioning Questionnaire (BDFQ) and the Level of Personality Functioning Scale (LPFS) was conducted following psychodynamic-oriented semi-structured interviews to assess the level of personality functioning. Hierarchical linear regression models were conducted. After controlling other variables, the predictability of LPFS components on global functionality was assessed. Global functioning was negatively correlated with subsyndromal depressive symptoms, the presence of a psychiatric comorbidity, alcohol/substance use disorders, the side effects of medication, poor social support, and an impaired level of personality functioning. Finally, a decrease in the level of personality functioning predicted impaired global functioning. The present study demonstrated that the level of personality functioning had a significant impact on global functioning during the euthymic period of BD. Therefore, the assessment of the level of personality functioning in patients with BD will aid in better understanding this population and in the design of long-term treatment plans.

Association between apolipoprotein E genotypes and panic disorder in Turkish population

Abstract Aim: In this study, we aimed to investigate possible interactions among the apolipoprotein E (ApoE) and panic disorder (PD), taking into account serum cholesterol levels and subfractions. Methods: ApoE genotyping was performed by real-time polymerase chain reaction in DNA samples of PD patient group (n = 45) and healthy control group (n = 50). The serum lipid levels, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) subfraction analysis were examined. Results: There was a significant difference of ApoE genotypes in patient and control groups. The E3/E3 genotypes lower whereas E4 allele carriers were significantly higher in PD group ApoE4allele carriers had 3.2-fold higher risk of PD. PD group had significantly lower LDL and HDL levels. In spite of the decreased levels of total LDL, antiatherogenic large LDL subgroup was significantly lower in a patient with PD. Antiatherogenic large HDL and Intermediate HDL levels were lower, while atherogenic small HDL subfraction was significantly higher in PD group. Furthermore, Apo E3/E3 genotype carriers had significantly higher large LDL, HDL, large HDL, intermediate HDL level, and also had highest HDL between all the groups. ApoE4 allele carriers while they had highest atherogenic small HDL level. Conclusion: E4 allele can be associated with PD as an eligible risk factor, the E3/E3 could be a risk-reducing factor for PD. Patients with PD not only had lower LDL and HDL levels but also they have higher atherogenic LDL and HDL subfractions. Also, E3/E3 genotype carriers had convenient but ApoE4 carriers had atherogenic plasma cholesterol levels and subfractions.

Neuronal nitric oxide synthase polymorphisms in obsessive-compulsive disorder

Abstract Background: Obsessive-compulsive disorder (OCD) is a mental disease characterized by recurrent and intrusive thoughts and repetitive behaviours that negatively affect the quality-of-life of the patients. Recent studies have implicated the participation of neuronal nitric oxide in OCD pathogenesis as a neurotransmitter modulator. Aims: To identify whether variations in neuronal nitric oxide synthase (nNOS) genes may render individuals susceptible to OCD development. Methods: This study examined nNOS polymorphisms in 100 OCD patients and 121 unrelated healthy controls by polymerase chain reaction and restriction enzyme digestion methods. Results: nNOS 276 C + genotype incidence was significantly higher in OCD patients than controls and conferred a 2-fold increased risk for OCD. No significant differences were observed in frequencies of nNOS 84 genotypes between patients and controls. Conclusion: This study shows an association between nNOS gene polymorphism and OCD. Exact mechanisms by which nNOS gene variants contribute to OCD pathogenesis need to be further investigated.