RESUMO
BACKGROUND: Etiology of polycystic ovary syndrome (PCOS) is attributed to genetic and environmental factors. One environmental factor is oxidative stress. Paraoxonase 1 (PON1) is an antioxidant high-density lipoprotein-associated enzyme encoded by the PON1 gene. The PON1 gene has been implicated in the risk for PCOS, the influence of which appears to come from single nucleotide variants (SNVs) at multiple genetic loci. However, association study reports have been inconsistent which compels a meta-analysis to obtain more precise estimates. METHODS: From 12 publications, extracted genotype data were used in two genetic procedures. First, linkage disequilibrium (LD) was used to group eight PON SNVs into three: LD1, LD2 and LD3. Second, frequencies of the variant (var), wild-type (wt) and heterozygous (het) genotypes were used for genetic modeling (allele-genotype for LD1 and standard for LD2 and LD3). Risk associations were expressed in terms of pooled odds ratios (ORs), 95% confidence intervals (CIs) and Pa-values. Evidence was considered strong when significance was high (Pa < 0.0001) and heterogeneity absent (I2 = 0%). Pooled effects were subjected to modifier (power), subgroup (Asian/Caucasian), outlier, sensitivity and publication bias treatments. Multiple comparisons were Bonferroni-corrected. RESULTS: This meta-analysis generated 11 significant outcomes, five in LD1, six in LD2 and none in LD3. All six LD2 outcomes did not survive the Bonferroni-correction but two of the five in LD1 did. These two core LD1 findings conferred greater odds of PCOS to the var allele in the highly significant (Pa < 0.0001) overall (OR 1.44, 95% CI 1.24-1.67) and Asian (OR 1.41, 95% CI 1.20-1.65) outcomes. Of these two core outcomes, the Asian effect was homogeneous (I2 = 0%) but not the overall (I2 = 29%). CONCLUSIONS: Of the eight PON SNVs examined, two (rs854560 and rs662) were associated with PCOS risk. These 1.4-fold increased risk effects rendered Asians susceptible to PCOS. High statistical power, high significance, zero to low-level heterogeneity, robustness and lack of bias in the core outcomes underpinned the strong evidence for association.
Assuntos
Arildialquilfosfatase/genética , Predisposição Genética para Doença/genética , Síndrome do Ovário Policístico/genética , Polimorfismo de Nucleotídeo Único , Alelos , Feminino , Frequência do Gene , Genótipo , Humanos , Desequilíbrio de Ligação , Razão de ChancesRESUMO
PURPOSE: Reported associations of interleukin-18 (IL-18) single-nucleotide polymorphisms (SNPs) with allergic rhinitis (AR) have been inconsistent, prompting a meta-analysis to obtain more precise estimates. METHODS: We synthesized data from 8 articles and examined 3 IL-18 SNPs. Two SNPs (rs360721 and rs187238), in linkage disequilibrium, were combined and termed RS1. The rs1946518 SNP was analyzed separately (termed RS2). The recessive, dominant, and codominant (multiplicative) genetic models were used to estimate ORs and 95% CIs. Subgroup analysis was ethnicity-based. Sources of heterogeneity were investigated with outlier treatment. Sensitivity analysis was used to assess robustness of the associative effects. Multiple comparisons were Holm-Bonferroni corrected. RESULTS: All significant (pa < 0.05) outcomes indicating increased risks were found in the dominant/codominant models in RS1 and RS2. Five aspects of differences marked the significant African (RS1) and overall (RS2) outcomes: (i) magnitude of effect (ORs): greater (3.01-5.15) versus less (1.20-1.47); (ii) precision of -effects (95% CIs): less (1.07-21.52) versus more (1.01-1.89); (iii) outlier treated: no versus yes; (iv) sensitivity outcomes: nonrobust versus robust (dominant model only); and (v) greater evidential strength for RS2 (pa = 0.002) compared to RS1 (pa = 0.02) rendered RS2 our core finding. These levels of statistical significance for RS1/RS2 enabled both to survive the Holm-Bonferroni correction. CONCLUSIONS: The core outcome indicating a 1.5-fold increased risk could render the IL-18 polymorphisms useful in the clinical genetics of AR. Future studies that could focus on other IL-18 SNPs may find deeper associations with AR than what we found here.
Assuntos
Predisposição Genética para Doença/genética , Interleucina-18/genética , Rinite Alérgica/genética , Humanos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Selenoproteins are involved in antioxidant defense, the redox signaling pathway and cell homeostasis. Primary studies have shown that single-nucleotide polymorphisms in the selenoprotein gene (SEP15) are associated with cancer risk. However, conflicting outcomes warrant a meta-analysis to obtain more precise estimates. Literature search yielded 18 case-control studies from 12 articles. We calculated pooled odds ratios (OR) and 95% confidence intervals (CI) of two SEP15 polymorphisms (rs5845 and rs5859) using standard genetic models (homozygous, recessive, dominant and codominant). Subgroup analysis was based on statistical power (80% cutoff) and cancer type (breast/respiratory/genitourinary/colorectal). Heterogeneity of the outcomes necessitated examining their sources (outlier treatment). Multiple comparison outcomes were corrected with the False Discovery Rate (PaF). Our core findings lay in the post-outlier recessive subgroup outcomes, where risks in the powered study (≥ 80%) was increased (OR 1.26, 95% CI 1.02-1.57, PaF = 0.047) while that in genitourinary cancer was protective (OR 0.29, 95% CI 0.20-0.43, PaF < 10-4). The potency of outlier treatment in unmasking significant associations and generating homogeneity provides good evidence of SEP15's role in cancer. In the clinical sense, selenium chemo-intervention may be of benefit among persons with particular SEP15 genotypes.AbbreviationsAnumber of unduplicated articles that contributed to instabilityAManalysis modelBnumber of robust comparisonsBCbreast cancerBLCbladder cancercDNAcomplementary deoxyribonucleic acidCIconfidence intervalCIDconfidence interval differenceCRCcolorectal cancerDdecreased riskEHeliminated heterogeneityFfixed-effectsFDRFalse Discovery RateGUCgenitourinary cancersGSgained significanceHBhospital-basedHWEHardy-Weinberg EquilibriumIincreased riskI2measure of heterogeneitykDakiloDaltonLAClaryngeal cancerLUClung cancermafminor allele frequencynnumber of studiesNnumber of comparisonsNMnot mentionedNOSNewcastle-Ottawa ScaleORodds ratioPaP value for associationPaδP value for association (pre-FDR)PaFP value for association FDR-correctedPbP value for heterogeneityPBpopulation-basedPCprostate cancerPRISMAPreferred Reporting Items for Systematic Reviews and Meta-AnalysesPROpre-outlierPSOpost-outlierRrandom-effects[R]referenceRCrespiratory cancersRNSretained non-significanceROSreactive oxygen speciesSEPselenoproteinsSEP15selenoprotein geneSNPsingle nucleotide polymorphismSWShapiro-Wilk testUSAUnited States of Americavvvariantwvheterozygouswwwild-type.
Assuntos
Neoplasias/genética , Selenoproteínas/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Humanos , Neoplasias/patologia , Polimorfismo de Nucleotídeo Único , Fatores de RiscoRESUMO
OBJECTIVE: Non-syndromic cleft lip, with or without cleft palate (NSCL/P), is a common craniofacial birth defect, the risk of which is influenced from multiple genetic loci. Association study outcomes between single nucleotide polymorphisms (SNPs) near the muscle segment homeobox gene 1 (MSX1) and NSCL/P have been inconsistent. This compels a meta-analysis to obtain more precise estimates. METHODS: From 15 publications, we examined 12 SNPs under six groups (SG), based on linkage disequilibrium. Pooled odds ratios and 95% confidence intervals were calculated under the standard genetic models. The pooled effects were subjected to subgroup, outlier, sensitivity, and funnel plot (publication bias) analyses. RESULTS: Three of the six SGs showed significant associations. SG1 and SG4 effects indicated reduced risks. SG1 outcomes were attributed to outlier treatment, which the Asian outcomes validated. In contrast, increased risks were observed in SG3. All these significant outcomes were deemed robust by sensitivity analysis with no evidence of publication bias. CONCLUSIONS: Our study shows eight MSX1 SNPs associated with risk of NSCL/P. SG1 and SG4 carriers are protected (up to 23%), but SG3 carriers are 1.3-fold susceptible. Outlier treatment unmasked the significant associations in SG1. Non-heterogeneity and robustness helped elevate the level of evidence in our significant findings.
Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Fator de Transcrição MSX1/genética , Genes Homeobox , Marcadores Genéticos , Predisposição Genética para Doença , Genótipo , Humanos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
BACKGROUND: An epigenetic approach to explaining endometrial carcinogenesis necessitates good understanding of Ras association domain family 1 isoform A (RASSF1A) promoter methylation data from primary studies. AIMS: Differential magnitude of reported associations between RASSF1A promoter methylation and endometrial cancer (EC) prompted a meta-analysis to obtain more precise estimates. METHODS: Literature search yielded eight included articles. We calculated pooled odds ratios (OR) and 95% confidence intervals and subgrouped the data by race. Sources of heterogeneity were investigated with outlier analysis. RESULTS: The pooled ORs indicated increased risk, mostly significant. The overall effect (OR 11.46) was reflected in the European outcome (OR 15.07). However, both findings were heterogeneous (I2=57-70%) which when subjected to outlier treatment, erased heterogeneity (I2=0%) and retained significance (OR 9.85-12.66). Significance of these pre- and post-outlier outcomes were pegged at P≤0.0001. Only the Asian pre-outlier (OR 6.85) and heterogeneous (I2=82%) outcome was not significant (P=0.12) but when subjected to outlier treatment, erased heterogeneity (I2=0%) and generated significance (OR 23.74, P≤0.0001). CONCLUSIONS: Consistent increased risk associations underpinned by significance and robustness render RASSF1A with good biomarker potential for EC.
Assuntos
Biomarcadores Tumorais/genética , Metilação de DNA , Neoplasias do Endométrio/genética , Proteínas Supressoras de Tumor/genética , Feminino , Humanos , Regiões Promotoras GenéticasRESUMO
BACKGROUND/AIMS: Reported associations of reproductive outcomes (RO) and polycystic ovary syndrome (PCOS) with genotypes of the Ile49Ser and -482A>G polymorphisms in the Anti-Müllerian hormone (AMH) gene and its type II receptor (AMHRII), respectively, have conflicting results. METHODS: PubMed, Google Scholar and Science Direct databases were searched for studies that investigated Ile49Ser and -482A>G in RO and PCOS. Using the metaanalytic approach, we estimated risk (odds ratio [OR] with 95% confidence intervals) using standard genetic models. RESULTS: All calculated summary effects were non-significant. Overall associations of Ile49Ser and -482A>G with RO were absent (OR 0.95-0.99, P = 0.76-0.96) but implied increased risk in PCOS (OR 1.07-1.17, P = 0.49-0.55). Where heterogeneity of the pooled ORs were present, its sources were explored using the Galbraith plot. Detection and omission of the outlying studies in both polymorphisms not only erased heterogeneity of the recalculated pooled outcomes but also changed direction of association, where null effects turned to increased risk (Ile49Ser in RO) and increased risk became reduced risk (-482A>G in PCOS). Implications of the Ile49Ser and -482A>G, effects pointed to protection for Caucasians (OR 0.64-0.89, P = 0.36-0.73) in RO and increased risk in PCOS (OR 1.19-1.45, P = 0.28-0.65). Asian effects in RO and PCOS were variable (OR 0.97-1.24, P = 0.58-0.91). CONCLUSIONS: In summary, we found no evidence of significant associations of Ile49Ser and -482A>G with RO and PCOS, although contrasting Ile49Ser effects were implied among Caucasians between RO (up to 0.36% reduced risk) and PCOS (up to 1.5-fold increased risk).
Assuntos
Hormônio Antimülleriano/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Síndrome do Ovário Policístico/genética , Polimorfismo de Nucleotídeo Único/genética , Receptores de Peptídeos/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Reprodução/genética , Feminino , Frequência do Gene , Heterogeneidade Genética , Humanos , Modelos GenéticosRESUMO
BACKGROUND: Reported associations of the G241R and K469E polymorphisms of the intercellular adhesion molecule-1 gene (ICAM-1) gene with endometriosis have differed in magnitude. MATERIALS AND METHODS: In a meta-analysis of six published case-control studies (from five articles), we estimated risk [odds ratio (OR) 95 % confidence intervals (CI)] of associations with these polymorphisms using the Review Manager 5.3 software. RESULTS: Based on 1213 cases and 1103 controls, overall analysis showed significant increased risk in the homozygous (OR 2.83, 95 % CI 0.99-8.10, p = 0.05), dominant (OR 1.86, 95 % CI 1.00-3.46, p = 0.05) and codominant (OR 2.15, 95 % CI 1.06-4.35, p = 0.03) models. Confined to the studies in Hardy-Weinberg Equilibrium erased the significance (OR 1.59-2.59, 95 % CI 0.81-8.22, p = 0.10-0.15). Asian effects were variable (OR 0.93-1.09, p = 0.50-0.57), but Caucasian effects were not (OR 4.09-13.60, p < 0.0001). Independent data for the late stages of endometriosis suggest protection of the ICAM-1 K469E polymorphism among the Asians (OR 0.91-0.95, p = 0.35-0.71). These effects were weak but non-heterogeneous (P heterogeneity = 0.17-0.57, I (2) = 0-40 %). CONCLUSION: In summary, strengths of the overall effects were consistency, significance and robustness but limited by their high heterogeneity. These strengths and limitations were also observed in the Caucasian subgroup which when tested for interaction against the contrasting Asian effects, highlighted Caucasian susceptibility (p = 0.004-0.01). The findings are an interplay of strengths and limitations, which warrant awareness of their interpretation as susceptibility markers for this disorder.
Assuntos
Endometriose/genética , Molécula 1 de Adesão Intercelular/genética , Povo Asiático/genética , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Razão de Chances , Reação em Cadeia da Polimerase , Polimorfismo Genético , Risco , População Branca/genéticaRESUMO
PURPOSE: The +331G/A progesterone receptor (PgR) gene polymorphism may influence risk of endometrial cancer. However, data from published studies have been controversial. To evaluate whether combined evidence shows an association between this polymorphism and endometrial cancer, we considered all available studies in a meta-analysis. METHODS: We searched PubMed and EMBASE and identified eight studies representing data for 3,790 cases and 6,458 controls. We estimated risk [odds ratio (OR) and 95 % confidence interval] of these associations, which were non-significant in the entire body of results. RESULTS: Overall effects indicated increased risks, slightly pronounced in the homozygous and recessive models (OR 1.16-1.17, p = 0.57-0.60). These effects were exacerbated when confined to studies in Hardy-Weinberg Equilibrium (OR 1.33-1.36, p = 0.33-0.35) and in the underpowered subgroup (OR 1.62-1.68, p = 0.27-0.30). The exception is the powered subgroup which showed reduced risk (OR 0.96-0.97, p = 0.92-0.93). None of the comparisons were heterogeneous, in fact, 10 of the 16 comparisons had zero heterogeneity (I (2) = 0 %). CONCLUSION: In summary, the non-significant results suggest that the PgR +331G/A polymorphism might not be a conspicuous low-penetrant risk factor for developing endometrial cancer.
Assuntos
Neoplasias do Endométrio/genética , Predisposição Genética para Doença , Receptores de Progesterona/genética , Feminino , Humanos , Razão de Chances , Polimorfismo Genético , Risco , Fatores de RiscoRESUMO
BACKGROUND: There is growing evidence that the ghrelin axis, including ghrelin (GHRL) and its receptor, the growth hormone secretagogue receptor (GHSR), play a role in cancer progression. Ghrelin gene and ghrelin receptor gene polymorphisms have been reported to have a range of effects in cancer, from increased risk, to protection from cancer, or having no association. In this study we aimed to clarify the role of ghrelin and ghrelin receptor polymorphisms in cancer by performing a meta-analysis of published case-control studies. RESULTS: In the overall analysis, homozygous and recessive associations indicated that the minor alleles of rs696217 and rs2075356 GHRL polymorphisms conferred reduced cancer risk (odds ratio [OR] 0.61-0.78). The risk was unchanged for breast cancer patients when analysed separately (OR 0.73-0.83). In contrast, the rs4684677 GHRL and the rs572169 GHSR polymorphisms conferred increased breast cancer risk (OR 1.97-1.98, p = 0.08 and OR 1.42-1.43, p = 0.08, respectively). All dominant and co-dominant effects showed null effects (OR 0.96-1.05), except for the rs572169 co-dominant effect, with borderline increased risk (OR 1.08, p = 0.05). CONCLUSIONS: This study suggests that the rs696217 and rs2075356 ghrelin gene (GHRL) polymorphisms may protect carriers against breast cancer, and the rs4684677 GHRL and rs572169 GHSR polymorphisms may increase the risk among carriers. In addition, larger studies are required to confirm these findings.
Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Neoplasias Colorretais/genética , Neoplasias Esofágicas/genética , Humanos , Linfoma não Hodgkin/genéticaRESUMO
BACKGROUND: Reported associations of progesterone receptor gene polymorphism (PROGINS) with endometriosis have been inconsistent. AIM OF THE STUDY: To evaluate the association between the PROGINS polymorphism and the risk of endometriosis. METHODOLOGY: A meta-analysis of 12 published case-control studies with a total sample size of 3,321 (1,323 cases/1,998 controls) was performed. We estimated the risk (odds ratio [OR] 95 % confidence intervals) of endometriosis association with the PROGINS polymorphism. RESULTS: An association between the presence of the variant allele and risk of endometriosis was found, more in the homozygous and recessive models (OR 1.41-1.43, p = 0.15-0.17), and less in the dominant and co-dominant models (OR 1.22, p = 0.11-0.15). Reanalysis without the studies whose controls deviated from the Hardy-Weinberg Equilibrium did not materially alter the dominant and co-dominant effects (OR 1.19-1.22, p = 0.19-0.32), but exacerbated the homozygous and recessive effects (OR 1.59, p = 0.09). The subgroups based on geography showed increased risk associations, consistently significant in the European (OR 1.52-2.72, p = 0.0008-0.03) but not in the Brazilian studies, where ORs ranged from reduced (OR 0.70-0.74, p = 0.54-0.61) to increased (OR 1.11, p = 0.75) risks. Heterogeneity was confined in all comparisons to the dominant and co-dominant models (I (2) = 38-70 %), except in the European subgroup, which had zero heterogeneity (I (2) = 0 %) in all genetic models, as did all homozygous and recessive effects. CONCLUSION: This meta-analysis provides a comprehensive profile of the role of the PROGINS polymorphism in endometriosis by exploring the magnitude of the summary effects with modifier analysis. This magnitude is expressed with modulation or exacerbation of the summary effects, as defined by the parameters of the analysis. Thus, the results showed trend towards an increased risk of the variant PROGINS allele and susceptibility for the endometriosis.
Assuntos
Endometriose/genética , Polimorfismo Genético , Receptores de Progesterona/genética , Alelos , Intervalos de Confiança , Feminino , Predisposição Genética para Doença/genética , Humanos , Razão de Chances , RiscoRESUMO
BACKGROUND: The geographical location of Egypt at the crossroads of several major cultural areas between North Africa and the Middle East has contributed to its population history. AIM: To analyse the genetic structure of the population living in two geographical parts of Egypt. SUBJECTS AND METHODS: A sample of 112 Egyptians from the North African part of Egypt (Ismailia sample) and a sample of 52 Egyptians from the Asian part Sinai, have been analysed using 10 Alu insertion polymorphisms. RESULTS: The results of the present study showed a significant genetic difference between the Sinai and Ismailia samples. The latter showed an evident genetic affinity with North African populations; whereas the Sinai sample was found to be genetically closer to the Middle East populations. The Sinai sample showed a low average heterozygosity, unlike that found in the Ismailia sample. CONCLUSION: This study provides new insights into the genetic structure of the Egyptian population living in a land bridge between Africa and Asia. Results suggest a genetic discontinuity between the Sinai population and that of the North African part of Egypt. This discontinuity would have been maintained thanks to geo-climatic and social factors.
Assuntos
Elementos Alu , Mutagênese Insercional , Polimorfismo Genético , Árabes , Egito , Marcadores Genéticos , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
Inconsistency of reported associations between the Pro919Ser polymorphism in the BRCA1 interacting protein 1 (BRIP1) gene and breast cancer prompted us to undertake a meta-analysis. Although investigated by fewer studies, we have also studied the risk associated with the two additional BRIP1 polymorphisms, C47G and G64A, and breast cancer riskWe conducted searches of the published literature in MEDLINE through PubMed up to October 2012. Individual data on 5,122 cases and 5,735 controls from eight published case-control studies were evaluated for the Pro919Ser polymorphism. Accordingly, C47G and G64A polymorphisms were studied in 1,539 cases and 1,183 controls, and 667 and 782, respectively.In the overall analysis, association was lacking between the Pro919Ser polymorphism and breast cancer risk (odds ratio [OR] 0.98-1.02), materially unchanged when confined to subjects of European ancestry (OR 0.96-1.03) or even in the high-powered studies (OR 0.97-1.03). In the menopausal subgroups, premenopausal women followed the null pattern (OR 0.94-0.98) for the Pro and Ser allele contrasts, but not for the Pro-Ser genotype comparison where significant increased risk was observed (OR 1.39, P = 0.002). The postmenopausal women (>50 years) exhibited a range of pooled effects from protection (OR 0.83, P = 0.11) in the Pro-Ser genotype to slightly increased risk (OR 1.12-1.16, P = 0.28-0.42) in the Pro and Ser allele comparisons. The G64A polymorphism effects were essentially null (OR 0.90-0.98), but C47G was found to confer non-significantly increased risk under all genetic models (OR 1.27-1.40).Upon conclusion, overall summary estimates imply no associations but suggest susceptibility among carriers of the C47G polymorphism and Pro-Ser genotype in premenopausal women. The premenopausal findings and variable outcomes in postmenopausal women require more studies for confirmation.
Assuntos
Neoplasias da Mama/genética , Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença , Polimorfismo Genético , RNA Helicases/genética , Estudos de Casos e Controles , Proteínas de Grupos de Complementação da Anemia de Fanconi , Feminino , Humanos , Menopausa/genética , Pré-Menopausa , População Branca/genéticaRESUMO
PURPOSE: Inconsistency of reported associations between the C1420T polymorphism in the cytosolic serine hydroxymethyltransferase (SHMT1) gene and colorectal cancer (CRC) prompted us to undertake a meta-analysis. METHODS: We conducted searches of published literature in MEDLINE through PubMed up to April 2012. Individual data on 5,043 cases and 6,311 controls from 15 published case-control studies were evaluated. Meta-analyses were performed on the compiled dataset. RESULTS: In the overall analysis, association was lacking between the C1420T polymorphism and CRC risk (odds ratio [OR] 0.96-1.04, p = 0.47-0.77), materially unchanged when reanalyzed without the Hardy-Weinberg equilibrium-deviating studies (OR 1.03-1.09, p = 0.22-0.55) or subjected to outlier treatment (OR 0.89-0.99, p = 0.10-0.8). In the ethnic subgroups, Europeans were susceptible (OR 1.11-1.17, p = 0.13-0.48) and Americans, slightly protected (OR 0.86-0.87, p = 0.49-0.61). The increased risk effects, however, became null following outlier treatment (OR 0.95-1.06). Test for interaction between decreased risk associations in the low-folate subgroup (OR 0.60-0.85, p = 0.009-0.03) with the susceptible effects in the high-folate category (OR 1.14-1.22, p = 0.19-0.32) was significant (p interaction = 0.004). CONCLUSIONS: Overall summary estimates imply no associations but suggest geography-specific effects of the SHMT1 polymorphism that render Europeans susceptible, but not Americans. Folate status appears to show an inverse association of this polymorphism with CRC.
Assuntos
Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/genética , Citosol/enzimologia , Glicina Hidroximetiltransferase/genética , Polimorfismo de Nucleotídeo Único/genética , População Branca/genética , Ácido Fólico/metabolismo , Humanos , Viés de PublicaçãoRESUMO
The multifactorial pathogenesis of severe malaria is partly attributed to host genes, such as those encoding cytokines involved in complex inflammatory reactions, namely tumor necrosis factor-alpha (TNF-α). However, the relationship between TNF-α -308G >A gene polymorphism (rs1800629) and the severity of Plasmodium falciparum (P. falciparum) malaria remains unclear, which prompts a meta-analysis to obtain more precise estimates. The present meta-analysis aimed to better understand this correlation and provide insight into its association in populations with different ethnicities. Literature search outcomes included eight eligible articles in which TNF-α -308G >A polymorphism was determined in uncomplicated malaria (UM) and severe malaria (SM) of P. falciparum as represented in the case and control groups. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated in standard homozygous, recessive, dominant, and codominant genetic models. Subgroup analysis was based on ethnicity, i.e., Africans and Asians. The analyses included overall and the modified outcomes; the latter was obtained without the studies that deviated from the Hardy-Weinberg Equilibrium. The significant data also underwent sensitivity treatment but not publication bias tests because the number of studies was less than ten. Interaction tests were applied to differential outcomes between the subgroups. Overall and HWE-compliant analyses showed no significant association between the TNF-α -308G >A polymorphism and susceptibility to P. falciparum SM (ORs = 1.10-1.52, 95%CIs = 0.68-2.79; Pa = 0.24-0.68). Stratification by ethnicity revealed that two significant associations were found only in the Asians favoring SM for dominant (OR = 1.95, 95% CI = 1.06-3.61, Pa = 0.03) and codominant (OR = 1.83, 95% CI = 1.15-2.92, Pa = 0.01) under the random-effects model, but not among the African populations. The two significant Asian associations were improved with a test of interaction with P-value of0.02-0.03. The significant core outcomes were robust. Results of the meta-analysis suggest that TNF-α -308G >A polymorphism might affect the risk of P. falciparum SM, particularly in individuals of Asian descent. This supports ethnicity as one of the dependent factors of the TNF-α -308G >A association with the clinical severity of malaria. Further large and well-designed genetic studies are needed to confirm this conclusion.
Assuntos
Predisposição Genética para Doença , Fator de Necrose Tumoral alfa , Humanos , Genótipo , Plasmodium falciparum/genética , Polimorfismo de Nucleotídeo Único , Fator de Necrose Tumoral alfa/genéticaRESUMO
An ecosystem perspective to restoring beneficial uses in Areas of Concern can be interpreted as a shift from the traditional elucidation of simple cause-effect relationships to a multicausal way of thinking that more effectively accommodates ecosystem complexity. This holistic management paradigm has also pervaded the contemporary ecological modeling practice, making compelling the adoption of more sophisticated ecosystem modeling tools. In this study, our primary objective is to develop a Bayesian hierarchical network of simple ecological models for Lake Simcoe, Ontario, Canada, aiming to establish a realistic representation of the causal connections among exogenous nutrient loading, ambient nutrient conditions, and epilimnetic plankton dynamics. In particular, we used a spatially explicit simple mass-balance model forced with idealized sinusoidal loading to predict total phosphorus concentrations. A structural equation model was then used to delineate the interplay among nutrients, ambient light conditions, phytoplankton, and herbivorous biomass. Our analysis highlights the strength of the causal linkages between total phosphorus and water clarity with phytoplankton as well as the capacity of zooplankton grazing to modulate the algal standing crop. Our Bayesian network is also used to examine the exceedance frequency of threshold values for total phosphorus (15 µg/L) and chlorophyll a (4 µg/L) concentrations under scenarios of phosphorus loading reduction. Our study suggests that a 15% phosphorus loading decrease will still result in >25% violations of the 4 µg chla/L value in the two embayments of Lake Simcoe (Cook's Bay and Kempenfelt Bay). The TP levels will decrease in response to the exogenous loading reductions and this improvement will be primarily manifested in the northcentral segments of the system.
Assuntos
Ecossistema , Lagos/análise , Fósforo/análise , Plâncton/crescimento & desenvolvimento , Animais , Teorema de Bayes , Clorofila/análise , Clorofila A , Modelos Biológicos , Modelos Químicos , OntárioRESUMO
The Val762Ala polymorphism poly [ADP-ribose] polymerase 1 (PARP1) gene [ADPRT (adenosine diphosphate ribosyltransferase) gene] affects enzymatic activity, which modulates cancer susceptibility among human populations. Individual data on 13,745 cases and 16,947 controls from 28 published case-control studies were re-evaluated. Odds ratios (OR) were estimated for ethnic group, cancer type, smoking joint effects and studies confined to the Hardy-Weinberg equilibrium. We applied subgroup, sensitivity and outlier analyses as well as the Bonferroni correction for multiple testing. The results show strong evidence that the variant (C) allele confers significant increased risk in the Chinese (OR 1.20-1.44, P < 0.0001-0.002), exacerbated by smoking (OR 1.66-2.53, P < 0.0001) and joint interaction with XRCC1 Arg399Gln (OR 1.39, P < 0.0001) as well as adjustment for tumor type (gastric carcinoma ORs 1.39-2.01, P < 0.0001). These significant effects were unaltered following conservative correction for multiple tests. By contrast, this procedure erased the protective significance in Caucasians, but not in two American subgroups, (i) those in the brain tumor category (0.77-0.79, P < 0.0001) and (ii) smokers in the dominant model (OR 0.86, P < 0.0001). These differential findings between the two ethnicities maybe correlated with significantly (P < 0.0001) greater allele frequency of the variant allele (C) among the Chinese compared to Caucasians. Our racial and tissue-specific summary estimates imply consideration of the Val762Ala polymorphism as candidate gene marker for screening cancer patients' best suited for PARP inhibitor therapy.
Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Neoplasias/genética , Especificidade de Órgãos/genética , Poli(ADP-Ribose) Polimerases/genética , Polimorfismo de Nucleotídeo Único/genética , Grupos Raciais/genética , Alelos , Substituição de Aminoácidos/genética , Povo Asiático/genética , China , Epistasia Genética , Humanos , Neoplasias/enzimologia , Neoplasias/etiologia , Poli(ADP-Ribose) Polimerase-1 , Viés de Publicação , População Branca/genéticaRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0200967.].
RESUMO
Background: The aim of this study was to investigate associations between polymorphisms in the Lysyl oxidase (LOX) gene with susceptibility to cancer. The role of LOX in carcinogenesis prompted several association studies in various cancer types; however the outcomes of these studies have inconsistent. Thus, we performed a meta-analysis to obtain more precise estimates. Materials and Methods: A literature search yielded 14 articles from which we examined five cancer groups: breast, bone, lung, gastrointestinal, and gynecological cancers. For each cancer group, pooled odds ratios (ORs) and confidence intervals (95% CIs) were calculated using standard genetic models. High significance (p-value for association [pa] < 0.00001), homogeneity (I2 = 0%), and high precision of effects (CI difference [CID] <1.0 [upper CI - lower CI]) comprised the three criteria for strength of evidence. We used sensitivity analysis to assess robustness of the outcomes. Results: We generated 28 comparisons from which 13 were significant (pa < 0.05), indicating increased risk, (OR >1.00) found in all cancer groups except breast (pa = 0.10-0.91). Of the 13, three met all criteria (core) for strength of evidence (pa < 0.00001, CIDs 0.49-0.56 and I2 = 0%), found in dominant/codominant models of gynecological cancers (ORs 1.52-1.62, 95% CIs 1.26-1.88) and codominant model of lung cancer (OR 1.44, 95% CI 1.19-1.74). These three were deemed robust. Conclusion: Based on the three core outcomes, associations of LOX 473G/A with lung, ovarian, and cervical cancers indicate 1.4-1.6-fold increased risks, underpinned by robustness and high statistical power at the aggregate level.
Assuntos
Biomarcadores Tumorais/genética , Carcinogênese/genética , Predisposição Genética para Doença , Neoplasias/genética , Proteína-Lisina 6-Oxidase/genética , Humanos , Neoplasias/epidemiologia , Polimorfismo de Nucleotídeo Único , Medição de Risco/métodos , Medição de Risco/estatística & dados numéricosRESUMO
Background: Reported associations of allograft rejection in kidney transplant patients with VEGF single nucleotide polymorphisms (SNPs) have been inconsistent between studies, which prompted a meta-analysis to obtain more precise estimates. Methods: Using the PICO elements, kidney transplant patients (P) were compared by genotype data between rejectors (I) and non-rejectors (C) in order to determine the risk of allograft rejection (O) attributed to the VEGF SNPs. Literature search of four databases yielded seven articles. To calculate risks for allograft rejection, four SNPs were examined. Using the allele-genotype model we compared the variant ( var) with the wild-type ( wt) and heterozygous ( var- wt) alleles. Meta-analysis treatments included outlier and subgroup analyses, the latter was based on ethnicity (Indians/Caucasians) and rejection type (acute/chronic). Multiple comparisons were corrected with the Bonferroni test. Results: Five highly significant outcomes (P a < 0.01) survived Bonferroni correction, one of which showed reduced risk for the var allele (OR 0.61, 95% CI 0.45-0.82). The remaining four indicated increased risk for the wt allele where the chronic rejection (OR 2.10, 95% CI 1.36-3.24) and Indian (OR 1.44, 95% CI 1.13-1.84) subgroups were accorded susceptibility status. Conclusions: Risk associations for renal allograft rejection were increased and reduced on account of the wt and var alleles, respectively. These findings could render the VEGF polymorphisms useful in the clinical genetics of kidney transplantation.
Assuntos
Transplante de Rim , Fator A de Crescimento do Endotélio Vascular , Aloenxertos , Humanos , Transplante de Rim/efeitos adversos , Polimorfismo de Nucleotídeo Único , Fator A de Crescimento do Endotélio Vascular/genética , Fatores de Crescimento do Endotélio VascularRESUMO
BACKGROUND: The reported association between an insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene and the risk for acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) remains controversial despite the publication of four meta-analyses on this topic. Here, we updated the meta-analysis with more studies and additional assessments that include adults and children within the context of the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Sixteen articles (22 studies) were included. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using three genetic models (allele, recessive and dominant), in which ARDS patients were compared with non-ARDS patients (A1) and healthy controls (A2). Mortality outcomes were also assessed (A3). The influence of covariates was examined by meta-regression. Bonferroni correction was performed for multiple pooled associations. Subgroup analyses based on ethnicity (Asians, Caucasians) and life stage (adults, children) were conducted. Heterogeneity was addressed with outlier treatment. RESULTS: This meta-analysis generated 68 comparisons, 21 of which were significant. Of the 21, four A1 and three A3 highly significant (Pa = 0.00001-0.0008) outcomes withstood Bonferroni correction. For A1, allele and recessive associations were found in overall (OR 0.49, 95% CI 0.39-0.61), Caucasians (OR 0.46, 95% CI 0.35-0.61) and children (ORs 0.49-0.66, 95% CI 0.33-0.84) analyses. For A3, associations were found in overall (dominant: OR 0.45, 95% CI 0.29-0.68) and Asian subgroup (allele/ dominant: ORs 0.31-0.39, 95% CIs 0.18-0.63) analyses. These outcomes were either robust, or statistically powered or both and uninfluenced by covariates. CONCLUSIONS: Significant associations of the ACE I/D polymorphism with the risk of ALI/ARDS were indicated in Caucasians and children as well as in Asians in mortality analysis. These findings were underpinned by high significance, high statistical power and robustness. ACE genotypes may be useful for ALI/ARDS therapy for patients with COVID-19.