Age-related macular degeneration (AMD) is the leading cause of blindness in industrialized countries. It is a genetically heterogeneous disorder. With the development of molecular biology and molecular genetics, multiple potentially causative genes have been identified. Current studies of susceptibility genes and genetic epidemiology of AMD are reviewed.
Blindness ; epidemiology ; genetics ; Chromosomes, Human ; genetics ; Genetic Predisposition to Disease ; Humans ; Macular Degeneration ; epidemiology ; genetics ; Molecular Epidemiology

BACKGROUNDNumerous studies have evaluated the association between interleukin-18 (IL-18) promoter gene -607C/ A (rs1946518) polymorphism and tuberculosis (TB) risk. However, the results remain apparently conflicting. The aim of this study was to investigate whether IL-18-607C/A polymorphism is associated with susceptibility to TB.

METHODSPublications addressing the association between the IL-18-607C/A polymorphism and TB risk were selected from the Pubmed, Cochrane Library, Embase, CNKI and Wanfang databases. Data were extracted from the studies by two independent reviewers. Statistical analysis was performed using RevMan 5.0.25 and STATA 11.0 software.

RESULTSEight case-control studies with a total of 1166 TB patients and 1734 controls were retrieved. Meta-analysis results showed significant association between IL-18-607C/A polymorphism and TB risk in all comparisons of the A allele versus C allele (OR=1.17, 95% CI 1.05-1.30, P=0.004), AA versus CC (OR=1.43, 95% CI 1.14-1.81, P=0.002), CA+AA versus CC (OR=1.20, 95% CI 1.01-1.42, P=0.04) and AA versus CA+CC (OR=1.30, 95% CI 1.07-1.58, P=0.007). In subgroup analysis by nationality, a significant association between IL-18-607C/A polymorphism and TB risk in the comparisons of A versus C, CA+AA versus CC and AA versus CA+CC (OR=1.22, 95% CI 1.07-1.38, P=0.002; OR=1.31, 95% CI 1.06-1.61, P=0.01; OR=1.32, 95% CI 1.07-1.63, P=0.01, respectively) were found in Chinese population but not in Indian and Iranian populations.

CONCLUSIONThis study suggests that the -607C/A polymorphism of IL-18 gene would be a risk factor for TB, especially in Chinese population. To further evaluate gene-to-gene and gene-to-environment interactions on -607C/A polymorphism and tuberculosis risk, more studies with thousands of patients are required.

Genetic Predisposition to Disease ; genetics ; Humans ; Interleukin-18 ; genetics ; Promoter Regions, Genetic ; genetics ; Tuberculosis ; epidemiology ; genetics

BACKGROUND AND OBJECTIVEThe relationship between myeloperoxidase G-463A genetic polymorphisms and lung cancer susceptibility has been studied extensively. However, the outcomes are not consistent. The aim of this study is to evaluate the relationship between myeloperoxidase genetic polymorphisms and lung cancer susceptibility by meta analysis.

METHODSDocuments published were retrieved through databases associated with the study. Taking into account the possibilities of heterogeneity of the studies, a statistical test for heterngeneity was performed. The odds ratio and 95% CI were used to evaluate the risks. The meta analysis was applied with RevMan software 4.2, and the forest plot and funnel plot of meta analysis were worked out.

RESULTSA total of 5 381 cases and 5 827 controls from studies for Caucasian and a total of 1 558 cases and 1 755 controls from studies for East Asians were included. For Caucasian the pooled OR was 0.91 (95% CI: 0.81-1.02); For East Asians, the pooled OR is 0.83 (95% CI: 0.63-1.09). Publication bias exits in the study for Caucasian, but not for East Asians.

CONCLUSIONThe results of this study indicated that the polymorphism of myeloperoxidase G-463A was not significantly associated with the lung cancer risk for Caucasian or East Asians. However, further studies for the East Asians is needed for the few subjects.

Genetic Predisposition to Disease ; genetics ; Humans ; Lung Neoplasms ; epidemiology ; genetics ; Peroxidase ; genetics ; Polymorphism, Genetic ; genetics

Brain Ischemia ; epidemiology ; genetics ; Genetic Predisposition to Disease ; Humans ; Pedigree ; Stroke ; epidemiology ; genetics

With the rapid development of human genome project, increased genetic and population-based association studies are focused on the identification of the underlying susceptibility genes and contributions from gene-environment interaction to common complex diseases. Whole-genome association study with high-density single nucleotide polymorphisms is one of the most important milestones in that process. However, problems still exist in study design, data processing, and results interpretation. Large-scale cohort study or population-based case-control design with sufficient statistical power, new approaches to assess the gene-gene and gene-environment interactions, as guarantee of the consistency and replicability of these researches are crucial in the exploration of the causes of these common complex diseases.
Genetic Markers ; Genetic Predisposition to Disease ; Genetics, Population ; Humans ; Linkage Disequilibrium ; Molecular Epidemiology ; Phenotype

OBJECTIVEThis meta-analysis was performed to summarize the association of the ADIPOQ rs2241766 and rs266729 polymorphisms with metabolic syndrome (MS) in the Chinese population.

METHODSWe searched for articles in MEDLINE via PubMed, EMBASE, HuGE Navigator, CNKI, and Wanfang databases and calculated odds ratios (ORs) with 95% confidence intervals (CIs) to determine the strength of associations in fixed- or random-effects models.

RESULTSWe included 21 articles in the meta-analysis: 17 reports of ADIPOQ rs2241766 with 3628 cases and 3000 controls and 8 of rs266729 with 2021 cases and 2226 controls. We found an increased risk of MS with the ADIPOQ rs2241766 polymorphism in some genetic models (allele model: OR=1.12, 95% CI: 1.03-1.21; dominant model: OR=1.15, 95% CI: 1.04-1.28; homozygote model: OR=1.22, 95% CI: 1.00-1.49) but no association with the ADIPOQ rs266729 polymorphism (allele model: OR=0.98, 95% CI: 0.82-1.17; dominant model: OR=0.90, 95% CI: 0.79-1.02; recessive model: OR=1.09, 95% CI: 0.85-1.39; homozygote model: OR=1.03, 95% CI: 0.80-1.33).

CONCLUSIONThe results of this meta-analysis suggest an association between the ADIPOQ rs2241766 polymorphism and MS in the Chinese population. G allele of ADIPOQ rs2241766 increases the risk of MS. Better designed studies with different ethnic populations and larger sample sizes are needed for assessing the relationship between ADIPOQ rs2241766 and rs266729 polymorphisms and MS in the future.

Adiponectin ; genetics ; metabolism ; China ; epidemiology ; Genetic Predisposition to Disease ; Genotype ; Humans ; Metabolic Syndrome ; epidemiology ; genetics ; Polymorphism, Genetic ; Risk Factors

BACKGROUNDInterleukin 10 (IL-10) is an important cytokine with anti-inflammatory, anti-immune and anti-fibrotic functions. This study aimed at evaluating the relationship between allele polymorphisms in the IL-10 promoter region and hepatitis B virus (HBV) or hepatitis C virus (HCV) infection.

METHODSThe odds ratios (ORs) of IL-10 allele distributions in patients with HBV or HCV infection were analyzed against healthy controls. All the relevant studies in PubMed were identified, and poor qualified studies were excluded. The meta-analysis software REVMAN 4.2 was applied for investigating heterogeneity among individual studies and summarizing all the studies. The publication bias was also evaluated.

RESULTSThis study demonstrated a significant association between the IL-10-592 A/C polymorphism and HBV infection in the Asian population under the overall effect size of allele A versus C. In our subgroup meta-analysis, we found a significant association of IL-10-592 A/C polymorphism to HCV infection susceptibility in Asian populations, although sensitivity analysis showed that the combined result was not associated with the worldwide population. Other IL-10 allele polymorphisms were not associated with HBV or HCV infection.

CONCLUSIONIL-10-592 A/C allele might be a risk factor for HBV or HCV in Asians but not in Europeans.

Alleles ; Genetic Predisposition to Disease ; genetics ; Hepatitis B ; epidemiology ; genetics ; Hepatitis C ; epidemiology ; genetics ; Humans ; Interleukin-10 ; genetics ; Polymorphism, Genetic ; genetics ; Promoter Regions, Genetic ; genetics

Numerous studies have been done to explore the association between mannose-binding lectin two (MBL2) gene polymorphisms and the risk of tuberculosis (TB). However, the results are inconsistent. We performed a meta-analysis to investigate whether polymorphisms in the MBL2 gene were associated with TB risk. Databases including PubMed, Medline, Chinese Biomedicine Database, China National Knowledge Infrastructure, Wanfang Database, and Weipu Database were searched to find relevant articles published up to 2 October, 2012. Odds ratio (OR) with 95% confidence interval (CI) was used to evaluate the strength of association. All statistical tests were performed by using Revman 5.1 software and STATA 11.0 software. Six case-control studies including 1106 cases and 1190 controls were accepted in the meta-analysis. The results indicated that individuals carrying the MBL2 codon 54 B allele may have an increased risk of TB as compared with AA homozygotes (BB+AB vs. AA: OR=1.52, 95% CI: 1.22-1.88), whereas MBL2 +4 P/Q was possibly not associated with TB susceptibility in Chinese population.
China ; epidemiology ; Codon ; genetics ; Genetic Markers ; genetics ; Genetic Predisposition to Disease ; epidemiology ; genetics ; Humans ; Mannose-Binding Lectin ; genetics ; Polymorphism, Single Nucleotide ; genetics ; Prevalence ; Risk Assessment ; Tuberculosis ; epidemiology ; genetics

The polymorphism at codon 129 (M129V) of the human prion protein gene (PRNP) is a known risk factor for Creutzfeldt-Jakob disease (CJD) in Caucasians. There are few reports of this polymorphism's effect on memory and on the risk of Alzheimer's disease (AD). The M129V genotype distributions among Asians are very different from Caucasians. Another polymorphism, codon 219 (E219K) is not found in Caucasians. We investigated two polymorphisms of PRNP, M129V (rs1799990) and E219K (rs1800014) in 297 Korean AD patients and 217 healthy subjects. The analysis of the genotype and allele distributions showed no significant difference between the AD patients and the controls in both polymorphisms (P=0.19 genotype, P=0.51 allele for M129V; P=0.64 genotype, P=0.50 allele for E219K). Also, the PRNP polymorphisms were not significantly associated with AD when the populations were stratified for the presence or absence of apolipoprotein E-e4 (ApoE-epsilon4) allele. These results suggest that the PRNP genetic variants are not associated with the risk for AD in Korean population.
Prions/*genetics ; Polymorphism, Genetic/*genetics ; Male ; Korea/epidemiology ; Humans ; Genotype ; Genetic Predisposition to Disease/genetics ; Female ; Codon/genetics ; Apolipoproteins E/genetics ; Alzheimer Disease/*epidemiology/*genetics ; Alleles ; Aged

OBJECTIVEThe aim of this study is to determine whether the SUMO4 M55V polymorphism is associated with susceptibility to type 2 diabetes mellitus (T2DM).

METHODSA meta-analysis was performed to detect the potential association of the SUMO4 M55V polymorphism and susceptibility to T2DM under dominant, recessive, co-dominant (homogeneous and heterogeneous), and additive models.

RESULTSA total of eight articles including 10 case-control studies, with a total of 2932 cases and 2679 controls, were included in this meta-analysis. The significant association between the SUMO4 M55V polymorphism and susceptibility to T2DM was observed in the dominant model (GG + GA versus AA: OR = 1.21, 95% CI = 1.05-1.40, P = 0.009), recessive model (GG versus GA + AA: OR = 1.29, 95% CI = 1.07-1.356, P = 0.010), homozygous model (GG versus AA: OR = 1.41, 95% CI = 1.06-1.56, P = 0.001), and additive model (G versus A: OR = 1.18, 95% CI = 1.08-1.29, P = 0.001), and marginally significant in the heterozygous model (GA versus AA: OR = 1.16, 95% CI = 0.98-1.36, P = 0.080). In subgroup analyses, significant associations were observed in the Chinese population under four genetic models excluding the heterozygous model, whereas no statistically significant associations were observed in the Japanese population under each of the five genetic models.

CONCLUSIONThe meta-analysis demonstrated that the G allele of the SUMO4 M55V polymorphism could be a susceptible risk locus to T2DM, mainly in the Chinese population, while the association in other ethnic population needs to be further validated in studies with relatively large samples.

Diabetes Mellitus, Type 2 ; epidemiology ; genetics ; Genetic Predisposition to Disease ; epidemiology ; genetics ; Humans ; Small Ubiquitin-Related Modifier Proteins ; genetics ; metabolism