A number of studies have assessed a relationship between the T102C polymorphism in the HTR2A gene with an increased risk of major depressive disorder (MDD), bipolar disorder (BPD), and schizophrenia (SCZ). However, the results have been inconsistent. Hence, we performed this study to further evaluate potential associations between the T102C polymorphism and MDD, BPD, and SCZ. The strength of separate associations between the T102C polymorphism and the risk of MDD, BPD, or SCZ was measured by ORs and 95% confidence intervals (CIs) in six genetic models. Cochran's chi-square-based Q-statistic and I(2) were used to evaluate the heterogeneity between studies. The funnel plot and the Egger's test were used to assess the publication bias. Cumulative meta-analysis was also performed to evaluate the trend in OR over time. No significant association was found in the overall analysis of MDD, BPD and SCZ with a sample size of 17,178 cases and 20,855 control subjects. In a further analysis by ethnicity, the OR and 95% CIs indicated the T102C polymorphism was not associated with MDD, BPD, or SCZ in Caucasian, Asian or Chinese populations. No publication bias was observed in the meta-analysis, and the cumulative analyses indicated the robust stability of the results. Thus, the results of our study indicate that the T102C polymorphism is not associates with increased susceptibility to MDD, BPD, and SCZ.

Association of the T102C polymorphism in the HTR2A gene with major depressive disorder, bipolar disorder, and schizophrenia.

Lithium is an effective, well-established treatment for bipolar disorder (BD). However, the mechanisms of its action, and reasons for variations in clinical response, are unclear. We used neural precursor cells (NPCs) and lymphoblastoid cell lines (LCLs), from BD patients characterized for clinical response to lithium (using the "Alda scale" and "NIMH Retrospective Life chart method"), to interrogate cellular phenotypes related to both disease and clinical lithium response. NPCs from two biologically related BD patients who differed in their clinical response to lithium were compared with healthy controls. RNA-Seq and analysis, mitochondrial membrane potential (MMP), cell viability, and cell proliferation parameters were assessed, with and without in vitro lithium. These parameters were also examined in LCLs from 25 BD patients (16 lithium responders and 9 non-responders), and 12 controls. MMP was lower in both NPCs and LCLs from BD; but it was reversed with in vitro lithium only in LCLs, and this was unrelated to clinical lithium response. The higher cell proliferation observed in BD was unaffected by in vitro lithium. Cell death was greater in BD. However, LCLs from clinical lithium responders could be rescued by addition of in vitro lithium. In vitro lithium also enhanced BCL2 and GSK3B expression in these cells. Our findings indicate cellular phenotypes related to the disease (MMP, cell proliferation) in both NPCs and LCLs; and those related to clinical lithium response (cell viability, BCL2/GSK3B expression) in LCLs.

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Lithium response in bipolar disorder correlates with improved cell viability of patient derived cell lines.

ObjectiveSchizophrenia (SCZ) and bipolar disorder (BD) are common psychotic disorders, which show some overlaps in genetic aetiology. Researchers have conducted a number of studies to investigate the relationship between SCZ and the 1354C/T genetic polymorphism of 5-hydroxytryptamine receptor 2A (HTR2A–1354C/T), as well as the associations between BD and the HTR2A–1354C/T polymorphism. However, the results were conflicting. To provide a more robust estimate about the effects of the HTR2A–1354C/T polymorphism on the risk of these two psychotic disorders, we performed this meta-analysis.MethodsWe used the pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) to investigate the relationships between SCZ and the 1354C/T polymorphism of HTR2A, as well as the associations between BD and HTR2A–1354C/T. Publication bias was tested by Begg's test and inverted funnel plot, and heterogeneity was checked by Cochran's Q statistic and the inconsistency index (I2).ResultsEight studies were concerned with SCZ, analysing a cumulative total of 2953 cases and 3153 controls; six papers studied BD, using a total of 923 cases and 928 controls. There was no significant association found between HTR2A–1354C/T and SCZ in the overall population (T allele vs. C allele, OR = 1.035, 95% CI 0.912–1.175, p = 0.596) or in the subgroups Caucasian population and Asian population. Moreover, there was no significant association between the HTR2A–1354C/T polymorphism and BD in the overall population (T allele vs. C allele, OR = 1.038, 95% CI = 0.607–1.772, p = 0.892).ConclusionOn the basis of these results, the HTR2A–1354C/T polymorphism is unlikely to be a risk factor for SCZ and BD.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/DB2A041B1FA152D6741ED2C08235D380/S092427081300015Xa.pdf/div-class-title-meta-analysis-of-the-span-class-italic-htr2a-span-1354c-t-polymorphism-in-schizophrenia-and-bipolar-disorder-div.pdf

Meta-analysis of the HTR2A–1354C/T polymorphism in schizophrenia and bipolar disorder

A study on candidate gene polymorphisms in association with mental retardation

Background: Genetic correlates of diseases of complex inheritance may include variations in several genes lying within a network of linked biological processes. Synaptic mechanisms, such as serotonin neurotransmission and second (third) messengers (e.g., glycogen synthase kinase [GSK]), have been implicated in susceptibility to mood disorders, the actions of therapeutic drugs and manipulation of circadian rhythms. A better understanding of such gene networks may be useful to understand the biology and treatment of mood disorders. Methods: We studied the association between serotonergic and GSK-mediated signaling networks with bipolar affective disorder (BPAD). We analyzed two single nucleotide polymorphisms (SNPs) in the HTR2A gene, a promoter SNP in SLC6A4 and a promoter SNP in the GSK3B gene in BPAD individuals and matched controls. A multifactor dimensionality reduction tool was employed to study gene–gene interactions and analyze multilocus genotype combination associations with high- or low-risk of B...

Identification of interaction between serotonin transporter and glycogen synthase kinase-3β gene polymorphisms: role in susceptibility to bipolar disorder

Ycj Reddy

Papers

Identification of interaction between serotonin transporter and glycogen synthase kinase-3β gene polymorphisms: role in susceptibility to bipolar disorder