Association of dopamine receptor polymorphisms with schizophrenia and antipsychotic response in a South Indian population

<p>Abstract</p> <p>Background</p> <p>Alterations in the dopamine transmission and receptor density are hypothesized in the pathophysiology of schizophrenia but ethnic disparities are reported to exist in disease association and therapeutic response to psychotropic medication. Antipsychotics have higher binding affinity to D2 subtype of dopamine receptor. DRD2 Cys311, TaqIB1 and TaqIA1 variants are considered to have either reduced affinity for dopamine and hypo-dopaminergic activity.</p> <p>Methods</p> <p>We examined the role of Taq1B, Taq1D, S311C, H313H and Taq1A polymorphisms of DRD2 gene in schizophrenia and antipsychotic treatment response in 213 patients and 196 controls from a homogenous South Indian population. A more detailed genotype phenotype association analysis was carried out to understand the disease in terms of its socio-cultural factors.</p> <p>Results</p> <p>H313HTT genotype was found to be associated with schizophrenia (P = 0.004) while TaqIB1B1 genotype was significantly associated with higher psychopathology score. When treatment response was considered H313HCC, TaqIA2A2 and Taq1D1D1 had higher mean improvement scores. TaqID1D1 and H313HTT genotype were found to be significantly higher in responders than in nonresponder group. Distinct shift in the LD patterns of responder and non-responder group was observed. Certain symptoms were characteristic of our patient population. Following medication the scores and presentation of these symptoms tend to vary in the responder and non-responder groups.</p> <p>Conclusion</p> <p>Based on genotype phenotype correlations it can be suggested that certain polymorphisms can be defined for their critical functions in disease and their role in treatment response in South Indian population. The present study suggests that in addition to ethnic bias, socio-cultural factors should also be considered while evaluating genotype phenotype correlations, in association and treatment response to complex disorders like schizophrenia.</p

Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission

AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p

Lack of association of Endoglin insertion polymorphism in intracranial aneurysm in South Indian population

Background : Endoglin , is a component of transforming growth factor-β complex. It is involved in vascular development and structural maintenance of the vessel wall. Conflicting reports on the association of a six base insertion polymorphism in intron 7 of the endoglin gene in intracranial aneurysms (IA) have been reported earlier. Materials and Methods: A case-control study was designed to compare 102 South Indian patients with intracranial saccular aneurysms and 118 ethnically and geographically matched healthy controls. The frequency of the six base insertion polymorphism was assessed by heteroduplex analysis followed by direct sequencing. Results:Insertion allele count was 39 (19.1%) of 204 alleles in the patient group and 42 (17.8%) of 236 alleles in the control group. The INS allele frequency was similar to the frequency in Caucasian population, but it was significantly lower than the Japanese population ( P =0.01). There was also no relationship of this polymorphism in patients with single aneurysm (33/176 alleles) or those with multiple aneurysms (6/28 alleles). Conclusion:Six base insertion polymorphism in Endoglin gene was not found to be a risk factor for intracranial saccular aneurysms in the South Indian population. Ethnic-related differences were observed. This is the first report on any genetic mutation in intracranial aneurysms in Indian population

Role of Endothelial Nitric Oxide Synthase Gene Polymorphisms in Predicting Aneurysmal Subarachnoid Hemorrhage in South Indian Patients

Endothelial nitric oxide synthase (eNOS) gene polymorphisms have been implicated as predisposing genetic factors that can predict aneurysmal subarachnoid hemorrhage (aSAH), but with controversial results from different populations. Using a case-control study design, we tested the hypothesis whether variants in eNOS gene can increase risk of aSAH among South Indian patients, either independently, or by interacting with other risk factors of the disease. We enrolled 122 patients, along with 224 ethnically matched controls. We screened the intron-4 27-bp VNTR, the promoter T-786C and the exon-7 G894T SNPs in the eNOS gene. We found marked interethnic differences in the genotype distribution of eNOS variants when comparing the South Indian population with the reported frequencies from Caucasian and Japanese populations. Genotype distributions in control and patient populations were found to be in Hardy-Weinberg equilibrium. In patients, the allele, genotype and estimated haplotype frequencies did not differ significantly from the controls. Multiple logistic regression indicated hypertension and smoking as risk factors for the disease, however the risk alleles did not have any interaction with these risk factors. Although the eNOS polymorphisms were not found to be a likely risk factor for aSAH, the role of factors such as ethnicity, gender, smoking and hypertension should be evaluated cautiously to understand the genotype to phenotype conversion

Lack of association of mirSNP rs11174811 in AVPR1A gene with arterial blood pressure and hypertension in South Indian population

Epigenetic regulation of arterial blood pressure mediated through mirSNPs in renin–angiotensin aldosterone system (RAAS) genes is a less explored hypothesis. Recently, the mirSNP rs11174811 in the 3’UTR of the AVPR1A gene was associated with higher arterial blood pressure in a large study population from the Study of Myocardial Infarctions Leiden (SMILE). The aim of the present study was to replicate the association of mirSNP rs11174811 with blood pressure outcomes and hypertension in a south Indian population. Four hundred and fifteen hypertensive cases and 416 normotensive controls were genotyped using a 5’ nuclease allelic discrimination assay. Logistic regression was used to test the association of mirSNP rs11174811 with the hypertension phenotype. Censored normal regression was used to test the association of the polymorphism with continuous blood pressure outcomes such as systolic and diastolic blood pressure. The mirSNP rs11174811 did not show any significant association with hypertension. The adjusted odds ratio was 1.02, with 95% CI of 0.72 to 1.45 (p = 0.909). The mean systolic and diastolic blood pressure values were not significantly different across the three genotypic groups, between hypertensives and normotensives, or when stratified by gender. Despite having a similar minor allele frequency (MAF) of 14.5% compared with the SMILE cohort, our results did not support an association of the mirSNP rs11174811 with the hypertension phenotype or with continuous blood pressure outcomes in the south Indian population

Severity of symptoms based on initial BPRS score compared with the BPRS score after one year follow up of medication in responder and non responder patients

<p><b>Copyright information:</b></p><p>Taken from "Association of dopamine receptor polymorphisms with schizophrenia and antipsychotic response in a South Indian population"</p><p>http://www.behavioralandbrainfunctions.com/content/3/1/34</p><p>Behavioral and brain functions : BBF 2007;3():34-34.</p><p>Published online 25 Jul 2007</p><p>PMCID:PMC1947997.</p><p></p