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ABSTRACT: Objective: Considering the suggested association of tryptophan hydroxylase gene 1 (TPH1) polymorphism with some psychiatric disorders and studies concerning serotonin’s effect on TPH 1 gene, brain and the neurotransmitter monoamines, as well as the studies performed on the serotonin levels in cerebrospinal fluid of bipolar patients, we aimed to investigate the frequencies and distribution of TPH 1 gene 218 A>C (rs1800532) polymorphism; A/A, A/C and C/C genotypes in bipolar patients and healthy control subjects for the first time in Turkish population (1-2).Methods: One hundred and sixteen adult patients who applied to the Mood Disorders Unit of Psychiatry Department, Medical School of Gaziantep University, and diagnosed with bipolar disorder (BD) according to DSM-IV diagnostic criteria were included in the study. One hundred and fifty healthy volunteers, a hospital staff at Gaziantep University, were involved as the control group.Results: In female patients, the frequency of A/A genotype was found to be higher than in the females in the control group. No significant difference was detected between patient and control groups in terms of age and gender distribution. The distribution of A/A, A/C and C/C genotypes were similar in patient and control groups. Conclusion: The distribution of TPH1 gene 218 A>C polymorphism was found to be significantly different between female patients and females in the control group. This result can be explicated as being one of the possible reasons for different course of bipolar disorder in male and female patients. (Archives of Neuropsychiatry 2010; 47: 96-100)
Nöropsikiyatri Arşivi. 01/2010;
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ABSTRACT: Acne is a multifactorial, chronic inflammatory disease of pilosebaceous unit in which cytokines have been implicated in the pathogenesis. Although it is thought to be an inherited disease, there are limited data supporting the relevant genetic elements. Tumor necrosis factor-alpha (TNF-alpha) is one of the proinflammatory cytokines involved in the acne pathogenesis. Several single-nucleotide polymorphisms (SNPs) have been identified in the human TNF-alpha gene promoter. The polymorphism at position -308, which involves substituting guanine (G) for adenine (A) (TNFA-308 G/A) has been linked to increased susceptibility to several chronic inflammatory diseases. The aim of this study was to determine the TNFA-308 G/A polymorphism in acne and to examine whether there is a relationship between this polymorphism and disease susceptibility. Exactly, 113 patients with acne and 114 healthy control subjects were included in the study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used for analysis of the TNFA-308 G/A polymorphism. We found that the frequency of the TNFA-308 GA genotype was statistically significantly increased in patients compared with healthy controls (P < 0.001). There was no association between TNFA genotypes and severity of acne (P > 0.05). There was also no significant difference between male and female patients. Our results suggest that TNFA-308 G/A polymorphism may contribute to a predisposition to acne in Turkish population.
Archives for Dermatological Research 07/2008; 300(7):371-6. · 2.28 Impact Factor
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ABSTRACT: It is hypothesized that molecular components of dopaminergic system, especially the dopamine D3 receptor gene (DRD3), may play a crucial role in the pathophysiology of schizophrenia, because it is abundant in the limbic system of the brain and it binds antipsychotic drugs. Several groups attempted to find an association between a serine-to-glycine polymorphism of the DRD3 gene (Ser9Gly) and schizophrenia; however, the results were inconsistent. In this study, we aimed to investigate the relationship of the Serine/Glycine polymorphism of the DRD3 gene with therapeutic response to clozapine treatment between Turkish schizophrenia patients (N = 92) and healthy controls (N = 100). Genotype groups were comparable in BPRS, SAPS, SANS analysis of response to clozapine. Our results suggest that an association between the Ser/Gly polymorphism of DRD3 gene and response to clozapine in Turkish schizophrenia patients is unlikely to exist.
American Journal of Medical Genetics Part B Neuropsychiatric Genetics 05/2008; 150B(1):56-60. · 3.70 Impact Factor
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ABSTRACT: Gamma oscillations (30-80 Hz) have been demonstrated to be important for perceptual and cognitive processes. Animal and in vitro studies have revealed possible underlying generation mechanisms of the gamma rhythm. However, little is known about the neurochemical modulation of these oscillations during human cognition. Schizophrenia and Attention Deficit Hyperactivity Disorder, which lead to failure of attentional modulation and working memory, introduce significant changes in gamma responses and have significant associations with genetic polymorphisms of dopamine receptor D4 (DRD4), dopamine transporter (DAT), and catechol-O-methyltransferase (COMT). Therefore, the presence of direct relations between these polymorphisms and gamma oscillations was investigated in human subjects using an auditory target detection paradigm. The 7-repeat isoform of the DRD4 polymorphism that produces a subsensitive variant of the D4 receptor enhanced the auditory evoked and induced gamma responses to both standard and target stimuli. The 10/10 genotype of the DAT1 polymorphism, which reduces DAT expression and hence yields an increase in extracellular dopamine, specifically enhanced evoked gamma responses to target stimuli. The COMT polymorphism did not significantly change gamma responses. It seems plausible to assume that the modulation pattern of the evoked gamma response by DRD4 polymorphism relates to reduced inhibition via the D4 receptor, whereas the DAT1 effect is related to the target detection mechanism probably mediated by the D1 receptor.
Cerebral Cortex 06/2007; 17(5):1007-19. · 6.54 Impact Factor
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ABSTRACT: To examine whether polymorphisms of the interleukin 1 receptor antagonist (IL1RN), interleukin 1 alpha (IL1A) and interleukin 1 beta (IL1B) genes are markers of genetic susceptibility to knee osteoarthritis in Turkish patients.
One hundred and seven patients with knee osteoarthritis and 67 controls were studied. Three polymorphisms of IL1A, IL1B, and IL1RN genes were typed from genomic DNA. Allelic frequencies were compared between patients and control subjects.
No significant differences were observed in genotype and allele frequencies of the IL1RN VNTR, IL1A+4845, IL1B+3953 genes polymorphisms between patients and controls. Furthermore, we did not detect any association genotypes of the polymorphisms with the clinical, radiological, and laboratory profiles of patients.
The present study suggest that the IL1RN VNTR, IL1A+4845, IL1B+3953 genes polymorphisms are not genetic markers of susceptibility to knee osteoarthritis in Turkish patients, and are unrelated to the clinical, radiological, and laboratory characteristics of knee osteoarthritis.
Clinical and investigative medicine. Medecine clinique et experimentale 02/2007; 30(2):E86-92. · 1.15 Impact Factor
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ABSTRACT: GABA(B)R (gamma-amino butyric acid B receptor)-mediated neurotransmission has been implicated in the pathophysiology of a variety of neuropsychiatric disorders. GABA(B)R1 gene variants were identified by single-strand conformation analysis. The nucleotide exchanges cause a substitution of alanine to valine in exon 1a1 (Ala20Val), a substitution of glycine to serine in exon 7 (Gly489Ser) and a silent C to G nucleotide exchange encoding the amino acid phenylalanine in exon 11 (Phe658Phe). The significance of GABA(B)R1a gene polymorphism in obstructive sleep apnea syndrome (OSAS) as well as the association of these polymorphisms with the polysomnography findings in OSAS patients are not known. In this study, we aimed to assess the significance of 3 different GABA(B)R1 gene polymorphisms (Ala20Val, Gly489Ser and Phe658Phe) in OSAS.
Seventy-five patients (23 female and 52 male) with OSAS and 99 healthy volunteers (51 female, 48 male) were included in the study to assess Ala20Val, Gly489Ser and Phe658Phe polymorphisms of the GABA(B)R1 gene.
For the Ala20Val variants, there was no significant difference between the genotypes and allele frequencies of the patients and controls, nor between both genders (p > 0.05). For Phe658Phe polymorphism, there was no significant difference between genotypes and allele frequencies of the patients and controls (p > 0.05). However, the C/C genotype was overrepresented and the T/C genotype was less frequent in male than female patients (p = 0.03). The C/C genotype was overrepresented and the T/C genotype was less frequent in male patients than male controls (p = 0.01). For GABA(B)R1-Gly489Ser polymorphism, all of the patients and controls had G/G genotype. The apnea arousal index scores of the male patients with C/C genotype were significantly higher than in the patients with C/T genotype (p = 0.01). The percent total sleep time in non-REM 1 scores of the male patients with T/T genotype were significantly higher than in the patients with T/C genotype (p = 0.021). The percent total sleep time in non-REM 2 scores of the female patients with C/C genotype were significantly higher than in the patients with C/T genotype (p = 0.006).
The Ala20Val polymorphism of the GABA(B)R1 gene may be associated with OSAS, whereas Gly489Ser polymorphism does not seem to be involved in OSAS. The C/C variant of the Phe658Phe polymorphism GABA(B)R1 gene seems associated with the occurrence of OSAS and is also associated with some sleep related parameters (apnea arousal index and percent total sleep time in non-REM) recorded by polysomnography.
ORL 01/2007; 69(3):190-7. · 0.91 Impact Factor
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ABSTRACT: Vitiligo is an acquired depigmentary disorder of the skin, characterized by incomplete penetrance, multiple susceptibility loci and genetic heterogeneity. An immunologic hypothesis is currently advanced as a possible pathogenesis of vitiligo. The cytokines have an important role in pathogenesis of autoimmunity in which tumor necrosis factor-alpha (TNF-alpha), a paracrine inhibitor of melanocytes, is especially important. Several single-nucleotide polymorphisms (SNP) have been identified in the human TNF gene promoter. The polymorphism at position -308 (TNF-308), which involves substituting G for A and designing the AA genotype, leads to a higher rate of TNF gene transcription than the wild-type GG genotype in in vitro expression studies. It has also been linked to increased susceptibility to several chronic metabolic, degenerative, inflammatory and autoimmune diseases. Therefore, we investigated the TNF-alpha-308 SNP in patients with vitiligo. We examined 61 patients with vitiligo. Healthy age-, ethnically- and sex-matched individuals (n = 123) served as controls. Polymerase chain reaction amplification was used for analysis of the polymorphism at position -308 in promoter of TNF-alpha gene. We found that the distribution of TNF-alpha genotypes in vitiligo patients did not differ from that in control subjects (P > 0.05). Moreover, there was no association between TNF-alpha genotypes and types of vitiligo. In conclusion, we suggest that TNF-alpha-308 SNP is not a genetic risk factor for vitiligo susceptibility.
Archives for Dermatological Research 07/2006; 298(1):46-9. · 2.28 Impact Factor
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ABSTRACT: Objective: To assess whether a relationship exists between G308A polymorphism of TNF-? gene and the temporomandibular dysfunction (TMD).Methods: 98 patients with temporomandibular dysfunction, and 132 healthy volunteer controls were included in the study. Molecular analysis of the G308A polymorphism of TNF-? gene was performed using PCR technique.Results: The ages and genders of the patients and controls were similar (Fisher exact test p = 0.5). There was no relationship between TNF 308GA polymorphism and TMD (?2 = 4.24, p = 0.12). The allele frequencies of the patients and controls were similar (?2 = 3.25, p = 0.076).
The Pain Clinic 03/2006; 18(2):175-180.
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ABSTRACT: Background and objective: To investigate the association between 308 G/A polymorphism of TNF-? gene and migraine.Methods: Polymerase chain reaction-restriction fragment length polymorphism assay was used to determine TNF-308 G/A polymorphism in 60 migraineurs and 62 healthy controls.Results: There was no significant relationship between TNF-??308 G/A polymorphism and gender, family history of epilepsy, family history of migraine and aura. In the control group, the frequencies of G and A alleles were 0.93 and 0.07, respectively. The corresponding values were 0.94 and 0.06 in the migraineurs. There was no significant difference between the allele frequencies and genotypes of the migraineurs and controls (p = 0.85).Conclusion: TNF-??308 G/A polymorphism is not associated with migraine and aura.
The Pain Clinic 09/2005; 17(4):389-393.
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ABSTRACT: Obstructive sleep apnea syndrome (OSAS) is a common condition characterized by repetitive pharyngeal collapse during sleep and daytime sleepiness. There is genetic predisposition to sleep disorders. Serotonin is involved in the regulation of sleep. The synaptic 5-hydroxytryptamine (HT) is inactivated by presynaptic reuptake, which is mediated by the serotonin transporter. Blockage of the serotonin transporter leads to increased extracellular 5-HT. Polymorphism of the serotonin transporter gene (STG) leads to alterations in serotonin level and may be important in OSAS. In this study, we aimed to assess the role of STG polymorphism in OSAS.
Twenty-seven OSAS patients and 162 healthy volunteers were involved in the study. STG polymorphism was investigated using leukocytes obtained from peripheral blood.
There was no difference between the genotypes and allele frequencies of the patients and controls regarding VNTR and HTTLPR polymorphisms (P > .05). The VNTR and HTTLPR variants and the frequencies of 12/12, 12/10, L, and S alleles were not significantly different between male and female control subjects (P > .05). The 12/12 and SS genotypes were over-represented in the female patients, whereas 12/10 and LL genotypes were over-represented in the male patients (P < .05). The genotypes 12 to 12 were over-represented in the male controls, whereas the genotypes 12 to 10 and L/S were over-represented in the male patients (P < .05). The alleles 10 and L were more frequent in the male patients than male controls (P < .05). The genotypes of female patients and female controls were not significantly different (P > .05). The allele 10 and L were less frequent in the female patients than female controls with Fisher's exact testing (P < .05). There was no relation between genotypes and clinical data of the patients (P > .05).
STG polymorphism appears to be associated with the occurrence of OSAS, especially in male patients. Absence of association of between genetic variants and polysomnography findings may suggest that some mechanisms other than STG polymorphism are involved in OSAS pathophysiology. Our results need confirmation in a larger group of patients with OSAS.
The Laryngoscope 05/2005; 115(5):832-6. · 1.75 Impact Factor
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The Pain Clinic 02/2005; 17(1):39-44.
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International Journal of Dermatology 05/2004; 43(4):312-4. · 1.14 Impact Factor
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ABSTRACT: Objective: To assess whether there is a relationship between monoamine oxidase-A (MAOA) gene promoter polymorphism and migraine in female patients.Study design: A polymerase chain reaction based study in which MAOA promoter polymorphism was studied in 54 female migraineurs and 52 controls.Methods: The low (3-repeat) and high (one of 3.5, 4 or 5 repeat units) activity MAOA alleles were detected. The genotypes and allele frequencies were compared both within and between the groups.Results: The representation of both low (1/1) and high (2/2) activity genotypes were similar between the female migraineurs and controls. The allele frequencies were also similar between these groups. There was no relationship between the presence or absence of aura and MAO polymorphism.Conclusion: MAOA gene polymorphism is not associated with migraine or aura in female patients.
The Pain Clinic 11/2003; 15(4):455-458.
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ABSTRACT: This study aimed to investigate the possible association between T102C and -1438 G/A polymorphism in the 5-HT2A receptor gene and susceptibility to and clinical features of obsessive-compulsive disorder (OCD).
Fifty-eight patients with OCD and 83 healthy controls were included in the study. All patients were interviewed and rated by Yale-Brown Obsessive-Compulsive Scale. T102C and -1438 G/A polymorphisms of 5-HT2A receptor gene were determined by PCR technique in DNAs of peripheral leucocytes.
OCD patients and healthy controls did not show significant differences in genotype distribution for both polymorphisms investigated. We found that frequencies of the TT genotype for T102C polymorphism and the AA genotype for -1438 G/A polymorphism were significantly higher in patients with severe OCD compared to those with moderate or moderate-severe OCD.
The -1438 G/A and T102C polymorphisms of the 5-HT2A receptor gene are not associated with an increased risk of OCD. Our data suggest that the TT genotype of T102C and the AA genotype of -1438 G/A polymorphism might be a factor in clinical severity of OCD.
European Psychiatry 09/2003; 18(5):249-54. · 2.77 Impact Factor
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ABSTRACT: The objective was to investigate possible association of the catechol o-methyl transferase (COMT) gene polymorphisms with myofacial pain syndrome (MFPS). The polymorphism of the COMT gene was compared between 49 patients with MFPS and 113 control subjects. Relationship between COMT polymorphism and psychiatric status of the patients was also assessed using SCL-90-R, BDS, and STAI-I and II tests. A PCR-based restriction fragment length polymorphism assay was used to detect G ? A transition at position 1947 in COMT. There was no relationship between MFPS and COMT polymorphism (p > 0.05). The patients who had MFPS without any temporomandibular joint problem had significantly higher expression of LL genotype when compared to those with joint problems (p < 0.05). There was no relationship between nocturnal bruxism and COMT polymorphism (p > 0.05). In conclusion, MFPS is not related to COMT polymorphism. COMT polymorphism is not associated with the psychiatric status of the patients. COMT polymorphism may be important for dose adjustment when the use of catechol drugs is anticipated.
The Pain Clinic 08/2003; 15(3):309-313.
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ABSTRACT: Objective: To find out the role of the 1438G/A polymorphism of the 5-HT2A promoter region in migraine.Study design: A polymerase chain reaction (PCR) analysis of the 1438G/A polymorphism was performed in 61 migraineurs and 57 healthy controls.Methods: The results of 1438G/A polymorphism were compared between the migraineurs and controls as well as between migraineurs with aura (MA) and those without aura (MOA).Results: The 1438 G/A polymorphism of 5-HT2A receptor gene was similar in both migraineurs and controls (p = 0.6). There was a significant relationship between the presence of G/G genotype and MA (p = 0.02) while A/A and A/G genotypes were similar in both MA and MOA (p > 0.05).Conclusion: The 1438G/A polymorphism of the 5-HT2A receptor gene is not associated with increased risk of migraine. The polymorphism of the gene is involved in determining the type of migraine. MA and MOA seem to be genetically distinct disorders.
The Pain Clinic 08/2003; 15(3):315-319.
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ABSTRACT: The pathophysiology of tardive dyskinesia (TD) is not completely understood.Aim. - To assess the relationship of TD with 5-HT2A receptor gene, serotonin transporter gene (5 HTT), and catechol-o-methyltransferase (COMT) gene polymorphisms.
Our study comprised 111 unrelated subjects who strictly met DSM-IV criteria for schizophrenia and 32 TD, and 79 healthy unrelated controls; all the subjects were of Turkish origin. The analyses of 5-HT2A receptor gene, 5 HTT gene, and COMT gene polymorphisms were performed using polymerase chain reaction (PCR) technique.
The polymorphisms of these genes were not significantly different between the schizophrenic patients, TD and control subjects.
Our findings indicated that 5-HT2A receptor gene, 5 HTT gene, and COMT gene polymorphisms were similar in schizophrenia with non-TD, schizophrenia with TD, and healthy controls. These polymorphisms, though, do not help to evaluate the susceptibility to TD.
European Psychiatry 04/2003; 18(2):77-81. · 2.77 Impact Factor
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ABSTRACT: The COMT gene has been implicated to be involved in the pathogenesis of obsessive-compulsive disorder (OCD) and various other psychiatric disorders. COMT enzyme activity is governed by a common genetic polymorphism at codon 158 that results in substantial 3- to 4-fold variation in enzymatic activity [a high-activity COMT variant (H) and a low activity variant (L)]. This study evaluates the association between OCD and the COMT gene polymorphism. Fifty-nine OCD patients that were diagnosed according to DSM-IV criteria and 114 healthy control subjects were included in the study. PCR technique was used for molecular analysis. The genotypic pattern of distribution of the COMT gene (H/H, H/L, and L/L genotypes) was not different between the OCD patients and controls. There were no significant differences among the patients with positive family history for OCD, those with negative family history for OCD, and the controls with respect to allele frequencies of the COMT gene polymorphisms. Patients that were homozygous or heterozygous for the L allele had significantly higher insight scores (i.e., poorer insight) on Y-BOCS compared to those homozygous for the H allele. We did not find an association between OCD, family history for OCD, and the COMT gene polymorphism. This study suggests that the COMT gene polymorphism is not directly associated with OCD in our patient group.
Depression and Anxiety 02/2003; 18(1):41-5. · 4.18 Impact Factor
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ABSTRACT: Serotonergic system abnormalities have been implicated in the pathogenesis of schizophrenia. The 5-HT2A receptor gene polymorphism has long been implicated to play a role in the pathogenesis of schizophrenia.
In this study, we assessed the relationship of schizophrenia and its subgroups with 5-HT2A receptor gene polymorphism, and attempted to evaluate a possible correlation between the severity and prognosis of the illness and 5-HT2A receptor gene polymorphism.
Our study comprised 141 unrelated subjects who strictly met DSM-IV criteria for schizophrenia, and 79 healthy unrelated controls, all of Turkish origin. A clinical evaluation of all patients was accomplished applying the Brief Psychiatric Rating Scale (BPRS) test. The analysis of 5-HT2A receptor gene polymorphism was performed using the polymerase chain reaction technique.
Regarding 5-HT2A receptor gene polymorphisms, no statistically significant difference was found between schizophrenic patients and control subjects (p > 0.05). There was no significant difference between the average of BPRS points of the patients and 5-HT2A receptor gene polymorphisms (p > 0.05). Although there was no correlation between the duration of illness and polymorphism (p > 0.05), the frequency of hospitalization was found to be higher in the patients with T/C and T/T genotypes compared with the patients with C/C genotype (p < 0.05).
Our findings indicate that the T102C polymorphisms of the 5-HT2A receptor gene does not play a substantial role in schizophrenia nor help evaluate susceptibility to schizophrenia. Since the 5-HT2A receptor gene polymorphism is associated with the frequency of hospitalization of the patients, it may be an indicator of prognosis in schizophrenia or help differentiate the patients who are somewhat refractory to antipsychotic treatment.
Neuropsychobiology 01/2003; 47(1):27-30. · 2.67 Impact Factor
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ABSTRACT: Variations in cathecholamine uptake and metabolism have been proposed as genetic susceptibility factors for Parkinson’s disease (PD) because of their role in the neurobiology of dopaminergic neurons. The aim of the study was to investigate the association of Parkinson’s disease with monoamine oxidase-A (MAO-A) gene polymorphism. Our results did not show any significant association of PD with the MAO-A variable numbers of tandem repeats in a sample of 76 unrelated PD cases and 76 healthy control subjects. This finding suggests that polymorphisms within the MAO-A gene do not play a major role in PD susceptibility in the Turkish population.
Journal of Neurological Sciences. 01/2003;
