Association of rs1801582 and rs1801334 PARK2 Polymorphisms with risk of Parkinson's disease: A case-control study in South India and Meta-Analysis

Genetic predisposition of LEPR (rs1137101) gene polymorphism related to type 2 diabetes mellitus - a meta-analysis

Background: Type 2 diabetes mellitus (T2DM) is a multifaceted disease appropriate to elevated blood glucose levels resulting from decreased insulin and beta-cell activity. Using a case-control methodology, researchers have examined the relationship between polymorphisms in LEPR and T2DM in a population from south India.Materials and Methods: We conducted a genetic analysis of 311 participants, and results were accomplished using a case-control study, a meta-analysis of previous studies on LEPR was conducted, and type 2 diabetes genotype distribution across various geographical regions Malaysians, Chinese Han, Kuwait, Iran, Mongolia, and Han Chinese, Greece, Saudi, India (North India, Punjabi), (South India, Tamilnadu). The study involved 254 prospective investigations, and nine association studies were preferred according to preset criteria. Studies were assessed for quality using the Hardy-Weinberg equilibrium (HWE) and the Newcastle-Ottawa Scale (NOS). An analysis of the genetic models was conducted to determine their relationship, statistical analysis was utilized to calculate odds ratios (ORs) and matching 95% confidence intervals (CIs).Results: The LEPR-rs1137101 polymorphism in the case-control study was associated with a significant increase in the risk of type 2 diabetes. A meta-analysis revealed a connection between LEPR gene polymorphism (rs1137101) and type 2 diabetes risk. Investigators might gain a more profound thought on the significance of the identified genetic variation and its impact on the chance of developing type 2 diabetes by verifying and strengthening previously reported findings. The model of fixed effects was chosen due to the low heterogeneity, and significant associations were observed in the allelic (OR = 0.79, 95% CI [0.70-0.87]), homozygote (OR = 0.58, 95% CI [0.46-0.72]), dominant (OR = 0.66, 95% CI [0.56-0.79]), and recessive (OR = 0.83, 95% CI [0.71-0.96]) genetic models. A Begg's funnel plot and Egger's test indicated no publication bias. These findings suggest that the rs1137101 variant in the LEPR gene has been linked to a higher risk of T2DM.Conclusions: A larger sample size, however, is required for further research, and consideration of potential confounding factors is needed to validate these associations. Understanding the implications of LEPR gene polymorphisms in T2DM susceptibility may contribute to personalized treatment strategies for patients with T2DM.

Investigation of PRKN Mutations in Levodopa-Induced Dyskinesia in Parkinson's Disease Treatment

Mitophagy is an important process that participates in mitochondrial quality control. Dysfunctions in this process can be caused by mutations in genes like PRKN and are associated with the development and progression of Parkinson's Disease (PD). The most used drug in the treatment of PD is levodopa (LD), but it can cause adverse effects, such as dyskinesia. Currently, few studies are searching for biomarkers for an effective use of lLD for this disease, especially regarding mitophagy genetics. Thus, this work investigates the association of 14 variants of the PRKN gene with LD in the treatment of PD. We recruited 70 patients with PD undergoing treatment with LD (39 without dyskinesia and 31 with dyskinesia). Genotyping was based on Sanger sequencing. Our results reinforce that age at onset of symptoms, duration of PD, and treatment and dosage of LD can influence the occurrence of dyskinesia but not the investigated PRKN variants. The perspective presented here of variants of mitophagy-related genes in the context of treatment with LD is still underexplored, although an association has been indicated in previous studies. We suggest that other variants in PRKN or in other mitophagy genes may participate in the development of levodopa-induced dyskinesia in PD treatment.

Somatic Mutations Detected in Parkinson Disease Could Affect Genes With a Role in Synaptic and Neuronal Processes

The role of somatic mutations in complex diseases, including neurodevelopmental and neurodegenerative disorders, is becoming increasingly clear. However, to date, no study has shown their relation to Parkinson disease’s phenotype. To explore the relevance of embryonic somatic mutations in sporadic Parkinson disease, we performed whole-exome sequencing in blood and four brain regions of ten patients. We identified 59 candidate somatic single nucleotide variants (sSNVs) through sensitive calling and a careful filtering strategy (COSMOS). We validated 27 of them with amplicon-based ultra-deep sequencing, with a 70% validation rate for the highest-confidence variants. The identified sSNVs are in genes with synaptic functions that are co-expressed with genes previously associated with Parkinson disease. Most of the sSNVs were only called in blood but were also found in the brain tissues with ultra-deep amplicon sequencing, demonstrating the strength of multi-tissue sampling designs.

Association between PPARγrs1801282 polymorphism with diabetic nephropathy and type-2 diabetes mellitus susceptibility in south India and a meta-analysis

BACKGROUND

Diabetic Nephropathy (DN) is a major complication of Type 2 Diabetes Mellitus (T2DM) with high morbidity rates worldwide.

OBJECTIVE

To determine the association of PPARγ rs1801282 polymorphism in T2DM and DN in south Indian population.

METHODS

We have conducted a case-control study to test the association of rs1801282 polymorphism with T2DM and DN in 424 subjects (DN=128; T2DM=148 and controls=148) belonging to the south Indian population using ARMS-PCR and Sanger sequencing method. Further, a meta-analysis was performed for rs1801282 polymorphism from the published literature retrieved from various electronic databases to determine the susceptibility among T2DM and DN across various ethnic populations under five genetic models.

RESULTS

The genotyping of rs1801282 polymorphism showed significant (p-value<0.05) association with DN and T2DM compared to controls. In the meta-analysis, no significant association (p-value>0.05) was noticed for rs1801282 with DN vs. controls in homozygote, heterozygote, allelic, recessive and dominant genetic models. However, a significant association was observed between rs1801282 SNP and T2DM under heterozygote (Jj vs JJ) genetic model with OR=0.56, (95%CI [0.43-0.74]), p≤0.0001 of Asian and Caucasian populations.

CONCLUSION

Overall analysis suggests that the rs1801282 polymorphism might be associated with DN and T2DM. More case-control studies on the PPARγ gene with a larger sample size including all the confounding factors are required to corroborate the findings from this meta-analysis.

Association between PPARγrs1801282 polymorphism with diabetic nephropathy and type-2 diabetes mellitus susceptibility in south India and a meta-analysis

BACKGROUND

Diabetic Nephropathy (DN) is a major complication of Type 2 Diabetes Mellitus (T2DM) with high morbidity rates worldwide.

OBJECTIVE

To determine the association of PPARγ rs1801282 polymorphism in T2DM and DN in south Indian population.

METHODS

We have conducted a case-control study to test the association of rs1801282 polymorphism with T2DM and DN in 424 subjects (DN=128; T2DM=148 and controls=148) belonging to the south Indian population using ARMS-PCR and Sanger sequencing method. Further, a meta-analysis was performed for rs1801282 polymorphism from the published literature retrieved from various electronic databases to determine the susceptibility among T2DM and DN across various ethnic populations under five genetic models.

RESULTS

The genotyping of rs1801282 polymorphism showed significant (p-value<0.05) association with DN and T2DM compared to controls. In the meta-analysis, no significant association (p-value>0.05) was noticed for rs1801282 with DN vs. controls in homozygote, heterozygote, allelic, recessive and dominant genetic models. However, a significant association was observed between rs1801282 SNP and T2DM under heterozygote (Jj vs JJ) genetic model with OR=0.56, (95%CI [0.43-0.74]), p≤0.0001 of Asian and Caucasian populations.

CONCLUSION

Overall analysis suggests that the rs1801282 polymorphism might be associated with DN and T2DM. More case-control studies on the PPARγ gene with a larger sample size including all the confounding factors are required to corroborate the findings from this meta-analysis.

Association of leucine-rich repeat kinase 2 gene rs10878307 polymorphism and Parkinson's disease risk in South India-A meta-analysis and molecular dynamics simulation

Communicated by Ramaswamy H. Sarma.

PSEN1 gene polymorphisms in Caucasian Alzheimer's disease: A meta-analysis

BACKGROUND

A meta-analysis was performed to assess PSEN1 gene polymorphisms (rs1800839 and rs17125721) in Alzheimer's disease (AD) risk.

METHODS

A systematic electronic search was performed across databases to retrieve studies published before 31 January 2017. The association between the selected PSEN1 polymorphisms and AD was based on five genetic models using DerSimonian and Laird's method or Mantel-Haenszel's method.

RESULTS

A total of 14 case-controlled studies were included. Results showed that rs1800839 polymorphism was significantly associated with AD in allelic OR=0.85 (95% CI [0.72-1.00]) and dominant OR=0.82 (95% CI [0.69-0.98]) genetic models, respectively. However, an insignificant association was found for rs17125721 polymorphism in all genetic models.

CONCLUSIONS

Meta-analysis of PSEN1 gene suggests that the rs1800839 polymorphism has potential influence on AD among Caucasians.

Association Between NOS1 Gene Polymorphisms and Schizophrenia in Asian and Caucasian Populations: A Meta-Analysis

Schizophrenia is a complex psychiatric disorder characterized by memory impairments with delusions and hallucinations. Several investigations have focused on determining the association between NOS1 (nitric oxide synthase-1) polymorphisms and risk of schizophrenia (SZ). However, the association of rs2682826, rs3782206, rs499776, rs3782219, rs41279104, rs3782221, rs1879417, rs4767540, rs561712, and rs6490121 polymorphisms with schizophrenia remains inconclusive. We performed a systematic meta-analysis for each polymorphism to determine its association with SZ by calculating their pooled odds ratio and 95% confidence intervals. The heterogeneity between studies was evaluated using Cochran's Q test to adopt random effects or fixed effects model. Based on our analysis, the rs3782206 polymorphism showed a strongest association with schizophrenia in allelic OR 1.15 (95% CI [1.05-1.25]), homozygote OR 1.35 (95% CI [1.09-1.66]), dominant OR 1.16 (95% CI [1.04-1.29]), and recessive OR 1.29 (95% CI [1.05-1.58]) models in Asian population. Similarly, in Caucasian population, the rs499776 polymorphism attributes risk association in homozygote OR 0.70 (95% CI [0.50-0.98]), dominant OR 3.57 (95% CI [2.34-5.27]), and recessive models OR 0.68 (95% CI [0.50-0.93]) with schizophrenia. Further, the sensitivity analysis was carried out based on leave-one-out method to confirm the reliability of the analysis. Overall, our meta-analysis demonstrates the significance of NOS1 genetic variants that are functionally associated with cognitive and neuropsychiatric symptoms of schizophrenia.

Genetic predisposition of IL-10 promoter polymorphisms with risk of multiple sclerosis: A meta-analysis

Interleukin-10 (IL-10) is a anti-inflammatory cytokine, which controls inflammation by inhibiting the synthesis of several cytokines produced by Th1 cells and macrophages. The association between Interleukin-10 promoter polymorphisms with the risk of multiple sclerosis (MS) remains inconclusive. In this study, a meta-analysis has been performed to assess the relationship between IL-10 gene polymorphisms rs1800896, rs1800871 and rs1800872 with the risk of MS. Nine case-control studies were selected involving 2755 participants. The association between the polymorphisms and MS was examined by the pooled odds ratios (ORs) with 95% confidence intervals (CIs) in allelic, homozygote, heterozygote, dominant and recessive genetic models. Of analyzed genetic models, the pooled ORs and CIs of each SNPs calculated based on random (I²>50) or fixed effects (I²<50) methods, which showed no significant association (p-value>0.05) of genetic predisposition with MS susceptibility across Asian and Caucasian populations. In addition, assessment based on funnel plot and Egger's linear regression test suggests no publication bias in all analyzed genetic models. Overall, our results demonstrated that rs1800896, rs1800871 and rs1800872 polymorphisms may not be the risk factor for the development of MS in both the populations.