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Introducción: La serotonina tiene gran implicación en la regulación del estado emocional y la ejecución de tareas cognitivas, de modo que los genes del transportador de serotonina (5-HTT, SLC6A4) y de los receptores de serotonina (HTR1A, HTR1B, HTR2A) se convierten en candidatos adecuados para estudiar los efectos de estos genes y sus variaciones polimórficas en las características de la depresión. Objetivo: Revisión de reportes de investigación que hayan estudiado los efectos de las variantes de los genes del transportador y de los receptores de serotonina en las diferentes características clínicas de la depresión. Métodos: Se realizó una búsqueda en las bases de datos Scopus, Web of Science y PubMed con las palabras clave "depression", AND "polymorphism". Conclusiones: Según la revisión de 54 artículos, se encontró que el alelo corto del polimorfismo de 5-HTTLPR es el factor de riesgo más reportado en relación con el desarrollo de depresión y su gravedad. Las variantes de los genes estudiados (SLC6A4, HTR1A, HTR1B y HTR2A) pueden generar alteraciones morfológicas de estructuras cerebrales.
Introduction: Serotonin is highly implicated in the regulation of emotional state and the execution of cognitive tasks, so much so that the serotonin transporter genes (5-HTT, SLC6A4) and the serotonin receptor genes (HTR1A, HTR1B, HTR2A) have become the perfect candidates when studying the effects that these genes and their polymorphic variations have on depression characteristics. Objective: A review of research reports that have studied the effects of variations in the serotonin transporter and receptor genes on different clinical features of depression. Methods: A search of the Scopus, Web of Science and PubMed databases was conducted using the keywords ("depression" AND "polymorphism"). Conclusions: According to the review of 54 articles, the short allele of the 5-HTTLPR polymorphism was found to be the most reported risk factor related to the development of depression and its severity. Variations in the genes studied (SLC6A4, HTR1A, HTR2A) can generate morphological alterations of brain structures.
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Abstract Genetic changes in platelet serotonin receptors (5-HTR2A) impair the initial process of tissue repair, regardless of the triggering factor of the skin wound. Objective was to determine the prevalence of the 102T-C polymorphism in the 5-HTR2A gene in Brazilian patients with and without skin wounds. Cross-sectional case-control study, in which 100 patients were evaluated as Cases Group (subdivided into I-with Chronic Wound and II-with Acute Wound) and 100 individuals as Controls, of both genders. DNA was extracted from leukocytes of peripheral blood and the region that covers the polymorphism was amplified by the molecular techniques Polymerase Chain Reaction/Restriction Fragment Length Polymorphism. The TT genotype was significantly associated with the protective factor against alterations in the healing process of skin wounds (OR: 0.4833; 95%CI: 0.2704-0.8638; p<0.05) in the Control Group. The genotypic analysis between Cases Group (I-Chronic Wound and II-Acute Wound) determined that the TT genotype was significantly associated with the protection factor in Case II (OR: 0.3333; 95%CI: 0.1359-0.8177; p<.005) and the CC genotype was significantly associated with the chance to develop chronic ulcers in the Case I (OR: 6.667; 95%CI: 1.801-24.683; p<0.05). Patients with chronic skin wounds have a higher prevalence of the 102T-C polymorphism in the 5-HTR2A gene, which is associated to alterations in the healing process in this population. There are differences, at the molecular level, in patients, with and without these lesions, and the probable role of the serotonergic system in wound healing.
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AIM: To investigate the association of dopamine D2 receptor (DRD2) and 5-hydroxytryptamine 2A receptor (5-HTR2A) gene polymorphisms and their interactions with efficacy of olanzapine in treatment of schizophrenic patients. METHODS: A total of 147 schizophrenic patients who treated with olanzapine alone were recruited. The positive and negative symptom scale (PANSS) was used to evaluate the efficacy of drugs. According to PANSS reduction rate ≥50% and <50%, patients were divided into the effective group and the ineffective group. The gene polymorphisms of DRD2 (rs1799978, rs1800497) and 5-HTR2A (rs6311, rs6313) were detected by improved multiple ligase detection reaction (iMLDR). Multivariate Logistic regression analysis was used to analyze the correlation between genotypes and olanzapine efficacy, and multifactor dimensionality reduction (MDR) was used to analyze gene-gene interactions. RESULTS: There were significant differences in genotype and allele frequencies of rs1799978 and rs6313 between the effective group and the ineffective group (P<0.05), while there was no difference in genotype and allele frequencies of rs1800497 and rs6311 (P<0.05). Patients with GA and GG of rs1799978 locus were more effective than those with wild type AA when treated with olanzapine, and the ORs (95%CI) were 5.101 (1.118-23.267) and 6.051 (2.454-14.925), respectively. Patients with CT and CC of rs6313 locus were more effective than those with wild type TT when treated with olanzapine, and the ORs (95%CI) were 2.623 (1.054-6.528) and 3.412 (1.180-9.869), respectively. There was a interaction between the gene polymorphisms of rs1799978, rs1800497 and rs6313. The interaction model was the optimal gene-gene interaction model (P<0.05) with the verify sample accuracy rate of 0.727 3 and a cross-validation consistency of 10/10. CONCLUSION: The gene polymorphisms of DRD2 (rs1799978) and 5-HTR2A (rs6313) may be associated with efficacy of olanzapine in treatment of schizophrenic patients, and there is a interaction between DRD2 (rs1799978, rs1800497) and 5-HTR2A (rs6313) on the efficacy of olanzapine.
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Abstract Background: Fibromyalgia (FM) is a chronic pain syndrome characterized by generalized skeletal muscle chronic pain. Its etiology is not well defined, because there are several factors that may trigger it such as physical and/or emotional stresses, or a genetic susceptibility, involving serotonergic, dopaminergic and catecholaminergic paths. The objective of this study was to investigate the association between the strength of the lower limb, genetic polymorphism of the serotonin receptor gene HTR2a in women with fibromyalgia. Methods: In this observational study of case-control type 48 women were evaluated who belonged to the group with FM (52 ± 12 years) and 100 women in the control group (58±11 years). Socio demographic and anthropometric data were collected and peripheral blood samples for DNA extraction; genotypic analyzes were performed by means of PCR in real time by TaqMan® system. The lower limb muscle strength was assessed through the test of sitting down and standing up for 30 s. The chi-square test or Fischer Exact was used for possible associations among the variables; the t-test for independent samples was used to compare the averages among the groups; the value of significance adopted was 5%. Results: There was an association between the polymorphism of the HTR2A gene with FM, demonstrating that carriers of the genotype GG have 24.39 times more likely to develop the syndrome (IC95% 5.15-115.47; p = 0.01). It was observed an association between FM and the test to sit and stand up demonstrating that women with fibromyalgia have lower limb muscle strength ( p = 0.01). The study showed that the white race has 3.84 times more likely to develop FM (p = 0.01). Conclusion: The results of this study suggest that women of Caucasian ethnicity with GG genotype or G allele presented greater risk of developing fibromyalgia and that these patients have lower limb muscle strength compared to the control group.
Subject(s)
Humans , Female , Polymorphism, Genetic , Fibromyalgia/physiopathology , Muscle Strength , Receptor, Serotonin, 5-HT2AABSTRACT
Background & objectives: Genetic factors have potential of predicting response to antidepressants in patients with major depressive disorder (MDD). In this study, an attempt was made to find an association between response to escitalopram in patients with MDD, and serotonin transporter (SLC6A4) and receptor (5HTR1A, 5HTR2A) polymorphisms. Methods: Fifty five patients diagnosed as suffering from MDD, were selected for the study. The patients were treated with escitalopram over a period of 6-8 wk. Severity of depression, response to treatment and side effects were assessed using standardised instruments. Genetic variations from HTR1A (rs6295), HTR2A (rs6311 and rs6313) and SLC6A4 (44 base-pair insertion/deletion at 5-HTTLPR) were genotyped. The genetic data of the responders and non-responders were compared to assess the role of genetic variants in therapeutic outcome. Results: Thirty six (65.5%) patients responded to treatment, and 19 (34.5%) had complete remission. No association was observed for genotype and allelic frequencies of single nucleotide polymorphisms (SNPs) among remitter/non-remitter and responder/non-responder groups, and six most common side-effects, except memory loss which was significantly associated with rs6311 (p=0.03). Interpretation & conclusions: No significant association was found between the SNPs analysed and response to escitalopram in patients with MDD though a significant association was seen between the side effect of memory loss and rs6311. Studies with larger sample are required to find out genetic basis of antidepressant response in Indian patients.
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Objective To investigate whether polymorphism of 102 T/C in 5-HTR2A (serotonin receptor 2A) are associated with Tourette syndrome (TS) in Chinese Han population or none.Methods A total of 101 TS patients and their parents were recruited for the study.The genetic contributions of the 5-HTR-2A 102 T/C polymorphism in 5HTR2A were evaluated using polymerase chain reaction and restriction enzyme digestion (PCRRFLP) and haplotype relative risk (HRR) and transmission disequilibrium test (TDT) statistics.Results The results revealed no significant associations between the 5-HTR-2A 102 T/C polymorphism and TS (HTR-2A 102T/C,TDT =0.353,df=1,P =0.621 ;HRR =1.127,x2 =0.358,P =0.550,95％ CI:0.762-1.666).Conclusion The data suggest that the HTR-2A 102 T/C polymorphism may not be associated with susceptibility to TS in the Chinese Han population.However,these results need to be replicated using larger datasets collected from different populations.
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BACKGROUND: Dopamine and serotonin receptors are candidate genes for the genetic study of schizophrenia because of their implication in the pathophysiology and etiology of schizophrenia (serotonine- dopamin hypothesis). A population-based association study was performed between schizophrenics and normal controls to identify the susceptibility genes. METHODS: A total of 145 schizophrenics and 242 normal controls were recruited. Ser9Gly polymorphism of DRD3, 12 bp repeat of DRD4, and 102T/C of HTR2A were selected as candidate polymorphism. The molecular techniques such as polymerase chain reaction (PCR)-restriction fragment length polymorphism and PCR-polyacrylamide gel electrophoresis were used. Chi-square analysis was performed to find any differences between two groups and logistic linear regression was tested to evaluate the interaction between three genes. RESULTS: There were no significant differences in allele frequencies and genotype frequencies of the three genetic polymorphism. Stratified by sex, the difference of DRD4 allele (P=0.065) and HTR2A allele (P=0.083) and genotype (P=0.054) was observed between male patients and controls; also noted was the difference of HTR2A genotype (P=0.080) between female patients and controls. Stratified by age of onset, the difference in the linear trend of DRD3 between early-onset patients and normal control (P=0.003) was observed. Stratified by family history, the difference in the linear trend of DRD4 (P=0.008) was also observed. Logistic linear regression with 90 patients who had early-onset phenotype (< or =20 year-old) or family history showed a significant result in interaction term (P=0.053). CONCLUSIONS: The finding that there were significant results only after stratification may imply a different genetic load on each subgroup of the disease. The interaction of genes between DRD3, DRD4, and HTR2A in a subgroup with supposedly high genetic background may support the serotonindopamine hypothesis. This, however, should be verified hereafter in large-scale studies.