Effects of Interaction between Angiotensin I‐Converting Enzyme Polymorphisms and Lifestyle on Adiposity in Adolescent Greeks

Genetic variation in the human angiotensin I‐converting enzyme (ACE) gene has been associated with many heritable traits, including obesity. Herein, we report the results of a study of obesity‐related phenotypes and lifestyle in 1016 teen‐aged Greeks. We show that there is a strong association (p = 0.001) between subcutaneous fat and the ACE insertion/deletion (I/D) polymorphism in females, possession of genotypes containing the D allele being associated with increased fat thickness. This association is strongest in females who participate in no extra exercise and accounts for 6.5% of the phenotypic variance in fat thickness by ANOVA. The association is additive, with the mean phenotypic values in heterozygotes intermediate between the means of the two homozygotes, and the association acts at both extremes of the fat thickness distribution in a classical polygenic manner. Other ACE polymorphisms (rs4424958, rs4311) that define major haplotypes in European populations fail to provide stronger associations with the subcutaneous fat phenotype. Because ACE I/D is the polymorphism most strongly associated with circulating ACE levels in European populations, we propose that the functional allelic differences that influence circulating ACE levels also mediate the associations with the obesity‐related phenotypes studied here.     

VEGF +936C/T and +460C/T gene polymorphisms and oral cancer risk: a meta-analysis

Many studies have examined the association between the VEGF +936C/T (rs833061) and +460C/T (rs3025039) gene polymorphisms and oral cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, we performed a meta-analysis. The PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases were searched for case–control studies that were published up to January 2013. Data were extracted and pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated. Ultimately, six studies were included, comprising 1006 oral cancer cases and 1016 controls. Overall, the pooled OR for VEGF +936 T allele carriers (TC + TT) versus the wild-type homozygotes (CC) was 1.28 (95 % CI 1.04–1.58; P = 0.228 for heterogeneity), the pooled OR for TT versus CC was 1.64 (95 % CI 1.34–1.98; P = 0.315 for heterogeneity), and the pooled OR for the T allele versus the C allele was 1.42 (95 % CI 1.22–1.76; P = 0.286 for heterogeneity). In the stratified analysis by ethnicity, significant risks were found among Caucasians but not Asians. However, there were no associations between VEGF +460C/T and oral cancer risk in only two of the included studies. In conclusion, this meta-analysis demonstrates that the VEGF +936 T allele may be associated with an increased risk of oral cancer, especially among Caucasian populations.     

Polymorphic variant at the IL2 region is associated with type 1 diabetes and may affect serum levels of interleukin-2

Polymorphic variants at the interleukin-2 (IL2) locus affect the risk of several autoimmune disorders. Our aim was to evaluate the association of the four IL2 polymorphisms (rs6822844, rs6534349, rs2069762 and rs3136534) with type 1 diabetes (T1D) in the Polish population, and to correlate them with the serum interleukin-2 levels. 543 unrelated T1D patients and 706 healthy control subjects were enrolled. The minor T allele at rs6822844 was significantly less frequent in T1D compared to controls (p = 0.002; OR 0.71; 95 % CI 0.571–0.880). Likewise, the frequency of the TT genotype was decreased among the affected individuals (p = 0.007). In healthy subjects, stratification according to the rs6822844 genotype revealed significant differences in circulating interleukin-2 (p = 0.037) with the highest levels in TT protective genotypes. Three other IL2 polymorphisms did not display significant differences in allele and genotype distribution. In conclusion, the rs6822844 variant is associated with T1D and may play a functional role, or reflect the influence of another causative genetic variant in linkage disequilibrium.     

Association of caspase 8 promoter variants and haplotypes with the risk of breast cancer and its molecular profile in an Iranian population: A case-control study

Caspase 8 (CASP8) gene plays a key role in the regulation of apoptotic cell death. Expression variation in this gene has been associated with the risk of breast cancer. The aim of this study was to investigate the association of rs3834129 and rs3769821, as functional variants, and their haplotypes with molecular profile as well as the risk of breast cancer in an Iranian population. A case-control study was conducted on 812 participants including 293 breast cancer patients and 519 healthy controls. Genotyping was performed by polymerase chain reaction–based methods. Statistical analysis was performed using SPSS Ver16. The association between polymorphisms and haplotypes with the risk of breast cancer was estimated by calculating odds ratios (OR) and chi-square (χ²) tests. In comparison with ins allele (I) of rs3834129, carriers of del allele (D) showed a lower risk of breast cancer (OR, 0.65; 95% confidence interval [CI], 0.49-0.87; P = 0.004). The multivariate logistic regression model indicated DD genotype as an independent factor for a decreased risk of breast cancer in our population (OR, 0.18; 95% CI, 0.06-0.58; P = 0.004). Also, the C allele of rs3769821 was associated with a 43% increased risk of breast cancer (P = 0.005); however, after adjustment for confounding factors, no association with rs3769821 and breast cancer was observed. In addition, D-T haplotype and diplotype presented protective effects (P < 0.05). Our results indicate that genetic variations in the promoter region of CASP8 gene, especially rs3834129, may serve as a genetic risk factor for breast cancer in an Iranian population.     

Molecular analysis of genetic variation in angiotensin I-converting enzyme identifies no association with sporting ability: First report from Indian population

INTRODUCTION:

A polymorphism in the angiotensin-converting enzyme (ACE) gene was the first performance enhancing polymorphisms (PEPs) to be identified and correlated with athletic abilities. This polymorphism (rs. 5186) is the absence (deletion; D allele), rather than the presence (insertion, I allele) of 287bp Alu repeat element in intron 16. However, the association of ACE I/D polymorphism in sports abilities have been contradicted and debated. No study has evaluated the ACE gene polymorphism in Indian athletes so far. Hence, the genotype distribution and allelic frequency of ACE gene in selected Indian athletic and non-athletic population was studied.

MATERIALS AND METHODS:

A total of 147 athletes and 131 controls were genotyped for the ACE gene polymorphism using PCR.

RESULTS:

No significant association was observed between the allelic frequencies of ACE gene in controls and athletes on a whole, as well as after sub-categorizing the athletes based on the type of sport they played (P > 0.1). However, a higher representation of I allele was observed in the athletes.

CONCLUSION:

ACE genotyping studies need to focus on truly elite athletes of a single sporting discipline, to be able to find an association. The ACE I/D polymorphism may not be considered a marker for human performance, but can be further studied in combination with other potent performance enhancing polymorphisms.     

Association of AGTR1 (A1166C) and ACE (I/D) Polymorphisms with Breast Cancer Risk in North Indian Population

Renin angiotensin system (RAS) comprising Angiotensin converting enzyme (ACE), Angiotensin II (Ang II) and its receptor Angiotensin II receptor type I (AGTR1), plays a critical role in several diseases including cancer. A single nucleotide polymorphism (SNP) A1166C located in 3′ untranslated region (UTR) of AGTR1 and an insertion/deletion (I/D) polymorphism present in intron 16 of ACE gene have been associated with many diseases, but their association with Breast cancer (BCa) is still debatable. Here, we for the first time investigated the association of these polymorphisms in a North Indian BCa cohort including 161 patients and 152 healthy women. The polymorphisms were evaluated by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) respectively. The association between these polymorphisms and BCa risk was estimated by calculating Odds Ratio (OR) and chi-square (χ²) test. The DD genotype/D allele of ACE (I/D) polymorphism and “AC and CC” genotype/C allele of AGTR1 (A1166C) polymorphism were associated with higher risk of BCa when evaluated independently. Furthermore, interaction analysis of “AC and CC” and DD genotype and combination of “C and D” alleles of both polymorphisms revealed significantly greater BCa risk than that observed independently. Conclusively, women harboring “AC or CC” genotype/C allele for AGTR1 (A1166C) polymorphism and DD genotype/D allele for ACE (I/D) polymorphisms have a predisposition to develop more aggressive disease with advanced staging and larger tumor size. Our study indicates importance of genetic screening based on these polymorphisms for women, who may have higher risk of BCa.     

Polymorphisms in vitamin D receptor,toll-like receptor 2 and Toll-Like receptor 4 genes links with Dengue susceptibility

Host genetic factors are known to determine disease susceptibility in dengue virus infection. Therefore, in this study association of gene polymorphisms of Vitamin D Receptor [rs731236 (Taq) and rs7975232 (Apa1)], Toll-like receptor 2 [rs5743708 (Arg735Gln) and rs5743704 (Pro631His)] and Toll-like receptor 4 [rs4986790A/G(Asp299Gly13843) and rs4986791 C/T(Thr399Ile)] were studied in cases with dengue as compared to controls. Total 98 cases of confirmed dengue virus infection and 98 age, sex and geographically matched healthy controls were enrolled and their genetic polymorphisms for the above mentioned regions were studied by Sanger sequencing. Mutant genotypes CC of VDR rs731236 (Taq1) [(OR 3.808, p value =0.02, CI 1.160-12.498)], GG of VDR rs7975232 (Apa1) [(OR 3.485, p value =0.02, CI 1.162-10.45)] and heterozygous genotypes of TLR4 rs4986790 A/G Asp299Gly [OR 2.40, p value= 0.02, CI 1.12-5.14], TLR4 rs4986791 C/T Thr399Ile [OR 2.09, p value=0.02, CI 1.12-5.14] were found to be significantly more in cases with dengue virus infection as compared to the controls. Also, at these positions mutant alleles were observed in significantly higher number of cases than controls. The values for C allele at VDR rs731236 (Taq1) were OR 1.86, p value 0.009, CI 1.162-3.001; for allele G at rs7975232( Apa1) were OR 2.71, p value 0.006, CI 1.196-2.98 for allele G at TLR4s rs4986790 A/G Asp299Gly were OR 2.35, p value 0.009, CI 1.23-4.50 and for allele T at rs4986791 C/T Thr399Ile were OR 2.36, p value=0.006, CI 1.28-4.38. VDR and TLR4 but not TLR2 gene polymorphisms were found to be associated with dengue susceptibility in Indian population.     

Angiotensin-converting enzyme I/D polymorphism and the risk of thoracic aortic dissection in Chinese Han population

Thoracic aortic dissection (TAD) is a catastrophic cardiovascular disease and is thought to have a genetic basis. Various studies have indicated that renin-angiotensin system plays an important role in the pathogenesis of aortic disease. To determine the association of the I/D polymorphism of ACE gene with the risk of TAD in a Chinese Han population, a hospital-based case–control study was designed consisting of 161 subjects with TAD and 256 control subjects. The genotype frequency of the ACE I/D polymorphism was determined by using a polymerase chain reaction assay. The overall distribution of ACE I/D genotypes was significantly different between the two groups. Compared with the controls, the frequency of DD genotypes and the D allele of ACE gene were significantly increased in TAD patients. Multivariate logistic regression adjusting for conventional vascular risk factors confirmed the association between the ACE I/D polymorphism and the susceptibility to TAD (OR 2.14, 95 % CI 1.38–3.32, P = 0.001). Our data demonstrated that the ACE I/D polymorphism appeared to be an important risk factor in the development of TAD. However, further validation in large population-based studies is needed to confirm the finding.     

Role of ACE and PAI-1 Polymorphisms in the Development and Progression of Diabetic Retinopathy

In the present study we determined the association of angiotensin converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) gene polymorphisms with diabetic retinopathy (DR) and its sub-clinical classes in Pakistani type 2 diabetic patients. A total of 353 diabetic subjects including 160 DR and 193 diabetic non retinopathy (DNR) as well as 198 healthy controls were genotyped by allele specific polymerase chain reaction (PCR) for ACE Insertion/Deletion (ID) polymorphism, rs4646994 in intron 16 and PAI-1 4G/5G (deletion/insertion) polymorphism, rs1799768 in promoter region of the gene. To statistically assess the genotype-phenotype association, multivariate logistic regression analysis was applied to the genotype data of DR, DNR and control individuals as well as the subtypes of DR. The ACE genotype ID was found to be significantly associated with DR (p = 0.009, odds ratio (OR) 1.870 [95% confidence interval (CI) = 1.04–3.36]) and its sub-clinical class non-proliferative DR (NPDR) (p = 0.006, OR 2.250 [95% CI = 1.098–4.620]), while PAI polymorphism did not show any association with DR in the current cohort. In conclusion in Pakistani population the ACE ID polymorphism was observed to be significantly associated with DR and NPDR, but not with the severe form of the disease i.e. proliferative DR (PDR).     

A missense variant in PTPN12 associated with the risk of colorectal cancer by modifying Ras/MEK/ERK signaling

BackgroundThe classical protein tyrosine phosphatases (PTPs) have been widely reported to be associated with various human malignancies including colorectal cancer (CRC). However, there are few comprehensive analyses of the association between the classical PTP genes and CRC risk.MethodsFirst, a bioinformatics analysis was performed to identify missense variants within the classical PTP gene family. Second, exome-wide association data and an independent population study were conducted to evaluate effects of candidate variants on CRC risk. Finally, functional assays based on signaling pathways were applied to uncover the potential pathogenic mechanism.ResultsWe identified that PTPN12 rs3750050 G allele presented a 19% increase the risk of CRC, with an OR of 1.19 (95% CI = 1.09–1.30, P = 1.015×10⁻⁴) under an additive model in the combined analysis. Furthermore, biochemical assays illustrated that rs3750050 could impair the inhibitory effect of PTPN12 on Ras/MEK/ERK signaling by impeding SHC dephosphorylation, increase the expression of cyclin D1 and ultimately lead to aberrant cell proliferation, thus contributing to CRC pathogenesis.ConclusionOur study highlights that PTPN12 rs3750050 could increase CRC risk by modifying Ras/MEK/ERK signaling. This work provides a novel insight into the roles of genetic variants within PTP genes in the pathogenesis of CRC.     

Lifestyle factors modify obesity risk linked to PPARG2 and FTO variants in an elderly population: a cross-sectional analysis in the SUN Project

Genetic factors may interact with lifestyle factors to modify obesity risk. FTO and PPARG2 are relevant obesogenes. Our aim was to explore the effect of Pro12Ala (rs1801282) of PPARG2 and rs9939609 of FTO on obesity risk and to examine their interaction with lifestyle factors in an elderly population. Subjects (n = 978; aged 69 ± 6) were recruited from the SUN (Seguimiento Universidad de Navarra) Project. DNA was obtained from saliva, and lifestyle and dietary data were collected by validated self-reported questionnaires. Genotyping was assessed by RT-PCR plus allele discrimination. Subjects carrying the Ala allele of PPARG2 gene had a significantly increased obesity risk compared to non-carrier (Pro12Pro) subjects (OR, 1.66; 95  % CI, 1.01–2.74; p = 0.045). Greater obesity risk was also found in inactive or high carbohydrate intake subjects with the Ala12 allele of PPARG2 gene. Interestingly, subjects carrying the Ala allele of the PPARG2 gene and with a high CHO (>246 g/day) intake had an increased obesity risk compared to Pro12Pro subjects (OR, 2.67; 95 % CI, 1.3–5.46; p = 0.007; p for [CHO × PPARG2] interaction = 0.046). Moreover, in subjects with a high CHO intake, the co-presence of the Ala allele of PPARG2 gene and one minor A allele (rs9939609) of FTO gene did increase obesity risk (OR, 3.26; 95 % CI, 1.19–8.89; p = 0.021) when compared to non-carrier (Pro12Pro/TT) subjects. In conclusion, it appears that lifestyle factors may act as effect modifiers for obesity risk linked to Ala12 allele of the PPARG2 gene and the minor A allele of FTO gene in an elderly population.     

Effects of Common Polymorphisms in the MTHFR and <Emphasis Type="Italic">ACE</Emphasis> Genes on Diabetic Peripheral Neuropathy Progression: a Meta-Analysis

Diabetic peripheral neuropathy (DPN) is a microvascular complication of diabetes mellitus. The aim of this meta-analysis was to evaluate the effects of methylenetetrahydrofolate reductase (MTHFR) 677 C>T and ACE I/D polymorphisms in the development of DPN. We systematically reviewed published studies on MTHFR 677 C>T and ACE I/D polymorphisms and DPN found in various types of electronic databases. Strengthening the Reporting of Observational studies in Epidemiology (STROBE) quality score systems were used to determine the quality of the articles selected for inclusion. Odds ratios (ORs) and its corresponding 95 % confidence interval (95 % CI) were calculated. We used STATA statistical software (version 12.0, Stata Corporation, College Station, TX, USA) to deal with statistical data. Our results indicated an association of ACE D>I mutation (OR?=?1.43, 95 % CI 1.12–1.83, P?=?0.004) and MTHFR 677 C>T mutation (OR?=?1.43, 95 % CI 1.08–1.90, P?=?0.014) with DPN under the allele model, and similar results were also found under the dominant model (all P?<?0.05). Subgroup analysis by country indicated that the MTHFR 677 C>T polymorphism may be the main risk factor for DPN in Turkey under four genetic models. ACE D>I mutation was correlated with DPN in Japanese and Pakistani populations in the majority of groups. The relationships of MTHFR 677 C>T and ACE I/D polymorphisms with DPN patients presented in this meta-analyses support the view that the MTHFR and ACE genes might play an important role in the development of DPN.     

Association between common genetic variants in pre-microRNAs and gastric cancer risk in Japanese population

Background: Common single‐nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human cancers. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre‐miRNAs (miR‐196a2, miR‐146a, and miR‐499) with the risk of gastric cancer (GC) and peptic ulcer diseases, and with the severity of Helicobacter pylori‐induced gastritis in Japanese population. Methods: The rs11614913 (C>T), rs2910164 (G>C), and rs3746444 (A>G) SNPs were genotyped in 552 GC, and 697 non‐cancer subjects, including 141 gastric and 73 duodenal ulcer, and 483 non‐ulcer subjects. The degree of histologic gastritis was classified according to the updated Sydney System, and the serum pepsinogen levels were measured in selected 579 and 204 cases. Results: The rs2910164 CC genotype held a significantly higher risk of GC when compared to non‐cancer subjects (adjusted odds ratio (OR) = 1.30, 95% confidence interval (CI) = 1.02–1.66, p =.03). Similarly, the rs2910164 C carrier was associated with higher risk of GC when compared to both non‐cancer and non‐ulcer subjects (OR = 1.39, 95%CI = 1.00–1.93, p =.05, adjusted OR = 1.57, 95%CI = 1.09–2.27, p =.016, respectively). The rs2910164 CC genotype was associated with non‐cardia and upper third, diffuse type and advanced stage GC. The rs11614913 TT genotype was associated with higher degree of mononuclear cell infiltration (score 0–1 vs 2～, adjusted OR = 1.62, 95%CI = 1.05–2.49, p =.03). Conclusions: The rs2910164 (G>C) SNP in the miR‐146a is associated with susceptibility to GC. In addition, the rs11614913 (C>T) SNP in the miR‐196a2 is associated with the degree of H. pylori‐induced mononuclear cell infiltration.     

Genetic Predisposition for Development of Nephropathy in Type 2 Diabetes Mellitus

The aim of the study was to explore the association of the angiotensin-converting enzyme (ACE) gene I/D polymorphism and the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism with development of diabetic nephropathy in type 2 diabetes mellitus. Three groups were recruited during 2007–2011: 232 normal controls, 185 type 2 diabetics without nephropathy, and 407 type 2 diabetics with nephropathy. The ACE I/D and MTHFR C677T polymorphisms were examined using PCR and PCR-RFLP methods. We found no significant association of the ACE I/D polymorphism with diabetic nephropathy in genotype, allele, dominant, and recessive models. We observed a significant association of MTHFR C677T with development of diabetic nephropathy in type 2 diabetics. The MTHFR C677T polymorphism plays a significant role in predisposition of renal insufficiency in diabetic patients.     

Biochip for determination of genetic markers of sporadic Alzheimer’s disease risk in the Russian Slavic population

A biological microchip (biochip) has been developed to study the genetic predisposition to sporadic form of Alzheimer’s disease (AD). The biochip allows of genotyping of ten genetic polymorphisms within APOE, TOMM40, APOJ, EXOC3L2, GAB2, A2M, CR1, BIN1, and PICALM genes. The assay includes the amplification of the loci of interest and subsequent allele-specific hybridization of the fluorescently labeled amplicons with oligonucleotides immobilized on the biochip. The genotyping of 166 patients and 128 controls revealed a significant association of APOE allele ?4 with susceptibility to AD (OR = 2.275, 95% CI 1.045–4.954, p = 0.034). Protective effects were observed for APOE allele ?2 and CLU (rs11136000) allele T (OR = 0.215, 59% CI 0.090–0.516, p = 0.001 and OR = 0.679, 95% CI 0.47–0.99, p = 0.042, respectively). A gene-gene interaction analysis revealed two AD-associated genotype combinations, APOE ?3/?4 GAB2 G/G (OR = 2.49, 95% CI 1.43–4.32, p = 0.001) and APOE ?4/?4 GAB2 G/G (OR = 3.55, 95% CI 1.23–10.24, p = 0.015). Based on the results of the combined multivariate analysis, an algorithm was developed to identify the individuals having a higher risk of AD.     

Association of IL10 Polymorphisms and Leprosy: A Meta-Analysis

Leprosy is a chronic infectious disease that depends on the interplay of several factors. Single nucleotide polymorphisms (SNPs) in host immune related genes have been consistently suggested as participants in susceptibility towards disease. Interleukin-10 (IL-10) is a crucial immunomodulatory cytokine in mycobacterial pathogenesis and especially the -819C>T SNP (rs1800871) has been tested in several case-control studies indicating association with leprosy risk, although a recent consensus estimate is still missing. In this study, we evaluated the association of the -819C>T SNP and leprosy in two new Brazilian family-based populations. Then, we performed meta-analysis for this polymorphism summarizing published studies including these Brazilian family-based groups. Finally, we also retrieved published studies for other distal and proximal IL10 polymorphisms: -3575 T>A (rs1800890), -2849 G>A (rs6703630), -2763 C>A (rs6693899), -1082 G>A (rs1800896) and -592 C>A (rs1800872). Results from meta-analysis supported a significant susceptibility association for the -819T allele, with pooled Odds Ratio of 1.22 (CI = 1.11–1.34) and P-value = 3x10^–5 confirming previous data. This result remained unaltered after inclusion of the Brazilian family-based groups (OR = 1.2, CI = 1.10–1.31, P-value = 2x10^–5). Also, meta-analysis confirmed association of -592 A allele and leprosy outcome (OR = 1.24, CI = 1.03–1.50, P-value = 0.02). In support of this, linkage disequilibrium analysis in 1000 genomes AFR, EUR, ASN and AMR populations pointed to r² = 1.0 between the -592C>A and -819C>T SNPs. We found no evidence of association for the other IL10 polymorphisms analyzed for leprosy outcome. Our results reinforce the role of the -819C>T as a tag SNP (rs1800871) and its association with leprosy susceptibility.     

Risk conferred by FokI polymorphism of vitamin D receptor (VDR) gene for essential hypertension

BACKGROUND:

The vitamin D receptor (VDR) gene serves as a good candidate gene for susceptibility to several diseases. The gene has a critical role in regulating the renin-angiotensin system (RAS) influencing the regulation of blood pressure. Hence determining the association of VDR polymorphisms with essential hypertension is expected to help in the evaluation of risk for the condition.

AIM:

The aim of this study was to evaluate association between VDRFok I polymorphism and genetic susceptibility to essential hypertension.

MATERIALS AND METHODS:

Two hundred and eighty clinically diagnosed hypertensive patients and 200 normotensive healthy controls were analyzed for Fok I (T/C) [rs2228570] polymorphism by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. Genotype distribution and allele frequencies in patients and controls, and odds ratios (ORs) were calculated to predict the risk for developing hypertension by the individuals of different genotypes.

RESULTS:

The genotype distribution and allele frequencies of Fok I (T/C) [rs2228570] VDR polymorphism differed significantly between patients and controls (χ² of 18.0; 2 degrees of freedom; P = 0.000). FF genotype and allele F were at significantly greater risk for developing hypertension and the risk was elevated for both the sexes, cases with positive family history and habit of smoking.

CONCLUSIONS:

Our data suggest that VDR gene Fok I polymorphism is associated with the risk of developing essential hypertension     

The Association of Sport Performance with ACE and ACTN3 Genetic Polymorphisms: A Systematic Review and Meta-Analysis

Background

Genetic polymorphism is suggested to be associated with human physical performance. The angiotensin I-converting enzyme insertion/deletion (ACE I/D) polymorphism and the α-actinin-3 gene (ACTN3) R577X polymorphism have been most widely studied for such association analysis. However, the findings are frequently heterogeneous. We aim to summarize the associations of ACE I/D and ACTN3 R577X with sport performance by means of meta-analysis.

Methods

We systematically reviewed and quantitatively summarized published studies, until October 31, 2012, on relationship between ACE/ACTN3 genetic polymorphisms and sports performance, respectively.

Results

A total of 366 articles on ACE and 88 articles on ACTN3 were achieved by literature search. A significant association was found for ACE II genotype compared to D allele carriage (DD+ID) with increased possibility of physical performance (OR, 1.23; 95% CI, 1.05–1.45). With respect to sport discipline, the II genotype was found to be associated with performance in endurance athletes (OR, 1.35; 95% CI, 1.17–1.55). On the other hand, no significant association was observed for ACTN3 RR genotype as compared to X allele carriage (XX+RX) (OR, 1.03; 95% CI, 0.92–1.15). However, when restricted the analyses to power events, a significant association was observed (OR, 1.21; 95% CI, 1.03–1.42).

Conclusion

Our results provide more solid evidence for the associations between ACE II genotype and endurance events and between ACTN3 R allele and power events. The findings suggest that the genetic profiles might influence human physical performance.     

CDKN2B-AS1 gene rs4977574 A/G polymorphism and coronary heart disease: A meta-analysis of 40,979 subjects

It has been implied that there is a possible relationship between cyclin-dependent protein kinase inhibitors antisense RNA 1 (CDKN2B-AS1) gene rs4977574 A/G polymorphism and coronary heart disease (CHD) susceptibility. However, as the research results are discrepant, no distinct consensus on this issue has been reached so far. In order to further elaborate the latent association of the CDKN2B-AS1 gene rs4977574 A/G polymorphism and CHD, this present meta-analysis was conducted. There were 40,979 subjects of 17 individual studies in the present meta-analysis. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were estimated to determine the association strength. Considering the significant heterogeneity among the individual studies, the random-effect models were used. In the current meta-analysis, a significant association between CDKN2B-AS1 gene rs4977574 A/G polymorphism and CHD was found under allelic (OR: 1.18, 95% CI: 1.08–1.29, p = 4.83×10⁻⁴), recessive (OR: 1.36, 95% CI: 1.11–1.67, p = 0.003), dominant (OR: 0.71, 95% CI: 0.58–0.86, p = 6.26×10⁻⁴), heterozygous (OR:1.210, 95% CI: 1.076–1.360, p = 0.001), homozygous (OR: 1.394, 95% CI: 1.163–1.671, p = 3.31×10⁻⁴) and additive (OR: 1.180, 95% CI: 1.075–1.295, p = 4.83×10⁻⁴) genetic models. A more significant association between them was found in the Asian population than that in the whole population under these genetic models (p < 0.05). However, no significant association between them was found in the Caucasian population (p > 0.05). CDKN2B-AS1 gene rs4977574 A/G polymorphism was associated with CHD susceptibility, especially in the Asian population. G allele of CDKN2B-AS1 gene rs4977574 A/G polymorphism is the risk allele for CHD.     

Genetic variants in metabolizing genes NQO1, NQO2, MTHFR and risk of prostate cancer: a study from North India

Quinone oxidoreductases (NAD(P)H): quinone oxidoreductase 1 (NQO1) and NRH: quinone oxidoreductase 2 (NQO2) are an antioxidant enzyme, important in the detoxification of environmental carcinogens. Methylene-tetra-hydrofolate reductase (MTHFR), plays a role in folate metabolism and may have oncogenic role through disruption of normal DNA methylation pattern, synthesis, and impaired DNA repair. In a case–control study, genotyping was done in 195 PCa and 250 age matched unrelated healthy controls of similar ethnicity to determine variants in NQO1 exon 4 (C?>?T, rs4986998), exon 6 (C?>?T, rs1800566), NQO2 ?3423 (G?>?A, rs2070999) and MTHFR exon 4 (C?>?T, rs1801133) by PCR–RFLP methods. Heterozygous genotype CT and variant allele career genotype (CT?+?TT) of NQO1 exon 4 showed increased risk of PCa (OR?=?2.06, p?=?0.033; OR?=?2.02, p?=?0.027). Variant allele T also revealed increased risk (OR?=?1.87, p?=?0.029). Similarly variant genotype TT (OR?=?2.71, p?=?0.009), combined genotype (CT?+?TT) (OR?=?1.59, p?=?0.019) and T allele (OR?=?1.63, p?=?0.002) of NQO1 exon 6 demonstrated significant risk for PCa. Diplotypes of NQO1 (exon 4 and 6), C–T (OR?=?1.56, Pc?=?0.007) and T–T (OR?=?0.011, Pc?=?3.86) was associated with an increased risk for PCa. NQO2 and MTHFR did not show any risk with PCa. Our results strongly support that common sequence variants and diplotypes of NQO1 exon 4 and 6 genes may have role in PCa risk in the North Indian population, indicating the importance of genes involved in metabolism with respect to PCa risk. Additional studies on larger populations are needed to clarify the role of variation in these genes in PCa carcinogenesis.