Single-Nucleotide Polymorphisms Associated with Mercury Levels and Neurological Symptoms: An Overview.

Mercury (Hg) pollution is a global public health concern because of its adverse effects on the environment and health. Single-nucleotide polymorphisms (SNPs) have been associated with Hg levels and outcomes. The aim of this review was to describe the research and discuss the evidence on the genetic susceptibility of Hg-exposed individuals to the development of neurocognitive disorders. A systematic review was performed to identify the genes/SNPs associated with Hg toxicokinetics and that, therefore, affect neurological function in exposed populations. Observational and experimental studies were identified by screening three databases. Thirteen articles were included (quality score 82-100%) and 8124 individuals were evaluated. Hg exposure was mainly fish consumption (77%) and, in 31% of the studies, the Hg levels exceeded the reference limits. Genetic susceptibility to higher Hg levels and neurotoxicity risk in Hg poisoning were associated with eight (ALAD rs1800435, CYP3A4 rs2740574, CYP3A5 rs776746, CYP3A7 rs2257401, GSTP1 rs1695, MT1A rs8052394, MT1M rs2270836, and MT4 rs11643815) and three (MT1A rs8052394, MT1M rs2270837, and MT2A rs10636) SNPs, respectively, and rs8052394 was associated with both outcomes. The MT1A rs8052394 SNP may be used as a susceptibility biomarker to identify individuals at greater risk for higher Hg levels and the development of neurocognitive disorders in metal-exposed populations.

Association of polymorphism in leptin receptor gene with susceptibility of adolescent idiopathic scoliosis.

PURPOSE: Abnormal leptin bioavailability has play key roles in the etiology of adolescent idiopathic scoliosis (AIS). Both leptin and its receptor levels may be modulated by the presence of genetic polymorphisms. This study aimed to evaluate the role of polymorphisms in the leptin (LEP) and its main receptor (LEPR) genes in the AIS susceptibility in girls. METHODS: A retrospective case-control study was conducted with 189 AIS and 240 controls. LEP rs2167270 and LEPR rs2767485 polymorphisms were genotyped using a TaqMan validated assay. Associations were evaluated by odds ratios (OR) and 95% confidence intervals (CI). RESULTS: The AIS group showed a predominance of girls under 18 years old (n = 140, 74.1%), 148 (78.3%) had low or normal BMI, 111 (58.7%) had Cobb ≥ 45º and 130 (68.7%) were skeletally mature. Minor allele frequencies of rs2167270 and rs2767485 were 35.7% and 18.3%, for AIS and 35.6% and 25.4% for controls, respectively. LEPR rs2767485 T and TC + TT were associated with higher risk of AIS (OR = 1.53; 95% CI = 1.09-2.13 and OR = 1.84; 95% CI = 1.69-2.01, respectively), since CC genotype was only present in the control group. In addition, the LEP rs2167270 GA + AA was more frequent in low weight group (BMI ≤ 24.9) of girls with AIS. There was no significant association between LEP rs2167270 and AIS susceptibility, and LEPR rs2767485 and BMI. CONCLUSION: The LEPR rs2767485 was associated with the genetic susceptibility of AIS and LEP rs2167270 with low BMI. These data can contribute to the identification of genetic biomarkers to improve the diagnosis and treatment.

Influence of interleukin-8 polymorphism on endometriosis-related pelvic pain.

Endometriosis presents a pro-inflammatory microenvironment influenced by cytokines, such as interleukin (IL)-8, which expression may be influenced by genetic polymorphisms. Therefore, we aimed to investigate the role of interleukin (IL)-8 rs4073 polymorphism in endometriosis' development and its related symptoms. A case-control study was conducted with 207 women with endometriosis and 193 healthy controls. Polymorphism was genotyped using a TaqMan validated assay. Associations were evaluated by binary logistic regression, using odds ratios (OR) and 95 % confidence intervals (CI), and P ≤ 0.05 was considered significant. Cases were younger (36 ± 6.8 versus 39 ± 8.4) and had lower body mass index (26.5 ± 5.3 versus 35.7 ± 6.3 Kg/m2) than controls (P < 0.001). Higher prevalence of symptoms and infertility was observed in cases, compared to controls (P < 0.001). Minor allele frequencies of IL-8 rs4073 (T) were 42.3 % and 39.9 % for cases and controls, respectively, and no associations were found between IL and 8 rs4073 polymorphism and endometriosis' prevalence or staging. However, the polymorphism was associated with chronic pelvic pain among cases (OR = 0.54; 95 %CI = 0.29-0.98). The IL-8 rs4073A > T polymorphism may contribute to lower IL-8 expression and, consequently, decrease endometriosis-related pelvic pain. These findings can support the early diagnosis of endometriosis' painful symptoms, preventing its complications, and allowing an individualized treatment.

Polymorphisms in paired box 1 gene were associated with susceptibility of adolescent idiopathic scoliosis: A case-control study.

Background: Association of genetic polymorphisms in paired box 1 (PAX-1) gene can influence the development of adolescent idiopathic scoliosis (AIS). PAX-1 is mainly expressed in the region of the vertebral bodies and intervertebral discs, being important for the proper formation of spinal structures. Objectives: The objective of this study was to evaluate the association of polymorphisms in PAX-1 gene with the susceptibility of AIS. Settings and Design: This was an analytical observational case-control study. Materials and Methods: Samples of 59 AIS indicated for surgical treatment, and 119 controls, without spinal disease were genotyped for PAX-1 rs6137473 and rs169311 polymorphisms. Statistical Analysis: The association of the polymorphisms with AIS was evaluated by a multivariable logistic regression model, using odds ratios (OR) and 95% confidence intervals (CI). Results: According to Lenke's classification, 89.8% had Type I and 10.2% II curves. The mean value of the Cobb angle of the proximal thoracic curve was 30.8°, 58.7° thoracic, and 30.4° for the lumbar and on the bending films 14.6°, 40.7°, and 11°, respectively. Among the AIS group, there was a predominance of females (8.8:1). The PAX-1 rs169311 and rs6137473 polymorphisms were positively associated with developing the AIS (OR = 1.98; 95% CI = 1.2-3.3 and OR = 3.16; 95% CI = 1.4-7.3, respectively). The rs6137473 polymorphism was associated with the lumbar modifier B and C compared to A (OR = 2.52; 95% CI = 1.1-5.8). Conclusions: PAX-1 polymorphisms were associated with an increased risk of developing the AIS and with curve severity and can be used as a biomarker to map the risk of developing surgical-grade AIS, guiding the treatment of patients.

DROSHA rs10719 and DICER1 rs3742330 polymorphisms in endometriosis and different diseases: Case-control and review studies.

OBJECTIVE: DROSHA and DICER1 enzymes participate in the main stages of microRNA synthesis. Polymorphisms can influence mRNAs stability and genes expression, and hence affect the binding of miRNAs. Thus, the present study evaluated the association of DROSHA and DICER1 polymorphisms in the development of endometriosis and other diseases. METHODS: A total of 240 endometriosis cases and 242 controls were genotyped for the DROSHA rs10719 G > A and DICER1 rs3742330 A > G polymorphisms using the TaqMan system. The association between polymorphisms and endometriosis was estimated by binary logistic regression. A literature review was also performed including all published articles (PubMed database) until December 2020, regarding the association of the studied polymorphisms and different diseases. RESULTS: DICER1 rs3742330GG was only found in endometriosis cases (2.1%) and deep infiltrative endometriosis (DIE) (2.5%). The DICER1 rs3742330GG genotype was significantly associated with endometriosis (P < 0.05), suggesting a tendency to present an increased risk for disease. DROSHA rs10719A and DICER1 rs3742330G allele frequencies varied among populations (6%-79% and 10.2%-55.1%, respectively). In the Brazilian population, the frequencies of these alleles were 42.3% and 7.3%, respectively. Both polymorphisms were risk factors for nonsyndromic orofacial clefts, tuberculosis, stroke ischemia and mortality after stroke, recurrent idiopathic pregnancy loss, and some types of cancer. Moreover, the DICER1 rs3742330 polymorphism was a protective factor for precancerous cervical lesions, different types of cancer and tuberculosis. CONCLUSIONS: The results suggest that only the DICER1 rs3742330 A > G polymorphism may be associated with susceptibility to endometriosis. The frequencies of both polymorphisms were significantly different among populations, and there were discrepancies in the risk associations with the development of diseases.

Systematic review of genome-wide association studies on susceptibility to endometriosis.

Endometriosis is a complex and heterogeneous disease in which extrinsic and intrinsic factors, such as genetics, provide to the disease development. Genome-wide association (GWA) studies may be essential to recognize genetic variants associated with the endometriosis risk. However, in the current literature there are some conflicting results between these studies. The aim of the present study was to undertake a systematic review about endometriosis GWA studies, to describe the disease-associated genes and single nucleotide polymorphisms (SNPs) to try to understand the endometriosis etiopathogenesis, besides to discuss possible bias of conflicting results among these studies. This study is a systematic review of GWA studies in endometriosis published until December 31th, 2019 by PubMed database, considering the following descriptors: endometriosis and ("polymorphism" or "SNP" or "genetic polymorphism" or "variants" or "locus") and ("GWA" or "Genome-wide" or "Genome wide" or "Genetic association study"). The included studies were analyzed with methodological rigor (STROBE and PRISMA) to enable better quality of case-control and meta-analysis studies, respectively. Of the 88 articles found, only 15 were eligible. All articles had appropriate quality evaluated by STROBE and PRISMA checklists (77% and 81%, respectively). Overall, 35,022 endometriosis cases and 181,760 controls were analyzed. The number of participants in each study was quite different (171 to 17,045 for the cases and 308 to 150,021 for the controls), with a predominance of European ethnicity. Most endometriosis cases (86%) were diagnosed by surgery, while selection of the control group was different among studies. About 47% performed only one stage (discovery stage) and 53% performed both the discovery and replication analyses. Eleven genes/SNPs were associated with endometriosis risk in more than one article (chromosome 1, 2, 6, 7, 9 and 12; WNT4, GREB1, FN1, IL1A, ETAA1, RND3, ID4, NFE2L3, CDKN2B-AS1 and VEZT). SNPs were localized in intergenic and intronic regions, their risk allele frequencies varied among the studies and their results were conflicting. In summary, WNT4 rs7521902, GREB1 rs13394619, FN1 rs1250248, IL1A rs6542095 and VEZT rs10859871 variants are highlighted due to high frequency and pathways and function that each gene influences in the development of endometriosis. However, the replication and validation of these variants in different populations are necessary for a better understanding of the endometriosis etiopathogenesis, in order to optimize the diagnosis and improve the efficiency of clinical treatment of the disease.

Epidemiological profile of women with endometriosis: a retrospective descriptive study / Perfil epidemiológico de mulheres com endometriose: um estudo descritivo retrospectivo

Abstract Objectives: to describe the epidemiological and clinical profile of women with endometriosis and to determine the association with the prognostic characteristics of the disease. Methods: retrospective descriptive study involving 237 women attended at two referral hospitals for endometriosis, between 2011 and 2017. Associations between groups were estimated using logistic regression models. Results: most women (65.4%) were of reproductive age (29-39 years), with a body mass index in the range of 18.5-24.9 kg/m2 and a high prevalence (23-81%) of symptoms of the disease, with 49.5% being infertile. The average time of diagnosis was 5 years. Ovarian endometrioma and/or deep infiltrative endometriosis (DIE) were the most frequent type of endometriosis (87%), and 59% of patients were in the III/IV stage of the disease. Approximately 87% of women with surgical diagnosis were aged over 30, married (70%) and had lower parity. Dyspareunia was negatively associated with superficial endometriosis. Infertility was positively associated with age (30-39 years) and DIE in the uterine tubes; dysmenorrhea with DIE in the uterosacral ligament; cyclic intestinal complaints with DIE in the rectosigmoid and intestine, and with DIE classification and III/IVstage. Conclusions: knowing the epidemiological and clinical profile of Brazilian women with endometriosis can help in diagnosis and treatment planning.

Resumo Objetivos: descrever o perfil epidemiológico e clínico de mulheres com endometriose e determinar a associação com as características prognósticas da doença. Métodos: estudo descritivo retrospectivo envolvendo 237 mulheres atendidas em dois hospitais de referência em endometriose, no período entre 2011 e 2017. As associações entre os grupos foram estimadas utilizando modelos de regressão logística. Resultados: a maioria das mulheres (65,4%) estava em idade reprodutiva (29-39 anos), com índice de massa corporal entre 18,5-24,9 kg/m2 e alta prevalência (23-81%) dos sintomas clínicos da doença, sendo que 49,5% eram inférteis. O tempo médio de diagnóstico foi de 5 anos. O endometrioma ovariano e/ou endometriose profunda infiltrativa (EPI) foram os tipos mais frequentes de endometriose (87%), sendo que 59% das pacientes estavam no estágio III/IVda doença. Aproximadamente 87% das mulheres com diagnóstico cirúrgico apresentavam idade acima dos 30 anos, eram casadas (70%) e apresentavam menor paridade. A dispareunia foi associada negativamente à endometriose superficial. A infertilidade foi associada positivamente com a idade (30-39 anos) e com a EPI nas tubas uterinas; a dismenorreia com a EPI no ligamento uterosacral; as queixas intestinais cíclicas com a EPI no retosigmóide e intestino, e com a classificação EPI e estágio III/IV. Conclusões: conhecer o perfil epidemiológico e clínico das mulheres brasileiras com endometriose pode auxiliar no diagnóstico e no planejamento do tratamento.

Role of cytochrome P450 2C19 polymorphisms and body mass index in endometriosis: A case-control study.

OBJECTIVE: To investigate the contribution of CYP2C19 polymorphisms and body mass index (BMI) in the development of endometriosis. STUDY DESIGN: This is a case-control study that includes 356 women (187 cases and 169 controls) recruited from two hospitals in the Brazilian public health system. The genotyping analyses of the CYP2C19*2 and CYP2C19*17 polymorphisms were performed using TaqMan allelic discrimination assays, and the association of the studied polymorphisms with endometriosis was evaluated by multivariate logistic regression. Pearson correlation coefficients were used to investigate the interaction between BMI and CYP2C19 polymorphisms. RESULTS: The variant allele frequencies of CYP2C19*2 were significantly different between cases and controls, and after adjusting for confounding factors, the CYP2C19*2 polymorphism was more frequent in women with endometriosis, considering all cases (CYP2C19*2: OR=1.83; 95% CI=1.17-2.85) and only deeply infiltrating endometriosis (DIE) cases (CYP2C19*2: OR=2.32; 95% CI=1.42-3.77). BMI was significantly lower in endometriosis patients (26.5±4.68) than in controls (27.8±5.65, P<0.02). Among obese women (BMI 30-40), the CYP2C19*2 polymorphism had a greater association with endometriosis (CYP2C19*2: OR=3.27; 95% CI=1.55-6.89). There was a positive correlation between CYP2C19*2 and BMI 30-40 (P=0.004). CONCLUSIONS: The findings of our study suggest that CYP2C19*2 is positively associated with endometriosis and that BMI may have a significant interaction with CYP2C19*2 and the risk of endometriosis.

Combined Effect of the PGR +331C > T, CYP17A1 -34A > G and CYP19A1 1531G > A Polymorphisms on the Risk of Developing Endometriosis.

Purpose To evaluate the magnitude of the association of the polymorphisms of the genes PGR, CYP17A1 and CYP19A1 in the development of endometriosis. Methods This is a retrospective case-control study involving 161 women with endometriosis (cases) and 179 controls. The polymorphisms were genotyped by real-time polymerase chain reaction using the TaqMan system. The association of the polymorphisms with endometriosis was evaluated using the multivariate logistic regression. Results The endometriosis patients were significantly younger than the controls (36.0 ± 7.3 versus 38.0 ± 8.5 respectively, p = 0.023), and they had a lower body mass index (26.3 ± 4.8 versus 27.9 ± 5.7 respectively, p = 0.006), higher average duration of the menstrual flow (7.4 ± 4.9 versus 6.1 ± 4.4 days respectively, p = 0.03), and lower average time intervals between menstrual periods (25.2 ± 9.6 versus 27.5 ± 11.1 days respectively, p = 0.05). A higher prevalence of symptoms of dysmenorrhea, dyspareunia, chronic pelvic pain, infertility and intestinal or urinary changes was observed in the case group when compared with the control group. The interval between the onset of symptoms and the definitive diagnosis of endometriosis was 5.2 ± 6.9 years. When comparing both groups, significant differences were not observed in the allelic and genotypic frequencies of the polymorphisms PGR +331C > T, CYP17A1 -34A > G and CYP19A1 1531G > A, even when considering the symptoms, classification and stage of the endometriosis. The combined genotype PGR +331TT/CYP17A1 -34AA/CYP19A11531AA is positively associated with endometriosis (odds ratio [OR] = 1.72; 95% confidence interval [95%CI] = 1.09-2.72). Conclusions The combined analysis of the polymorphisms PGR-CYP17A1-CYP19A1 suggests a gene-gene interaction in the susceptibility to endometriosis. These results may contribute to the identification of biomarkers for the diagnosis and/or prognosis of the disease and of possible molecular targets for individualized treatments.

Objetivo Avaliar a magnitude de associação de polimorfismos nos genes PGR, CYP17A1 e CYP19A1 no desenvolvimento da endometriose. Métodos Este é um estudo retrospectivo do tipo caso-controle, envolvendo 161 mulheres com endometriose (casos) e 179 controles. Os polimorfismos foram genotipados pela reação em cadeia da polimerase em tempo real utilizando o sistema TaqMan. A associação dos polimorfismos estudados com a endometriose foi avaliada pela regressão logística multivariada. Resultados As pacientes com endometriose eram significativamente mais jovens do que os controles (36,0 ± 7,3 versus 38,0 ± 8,5, respectivamente, p = 0,023), apresentaram um índice de massa corporal menor (26,3 ± 4,8 versus 27,9 ± 5,7, respectivamente, p = 0,006), maior tempo médio de duração do fluxo menstrual (7,4 ± 4,9 versus 6,1 ± 4,4 dias, respectivamente, p = 0,03) e menor tempo médio do intervalo entre as menstruações (25,2 ± 9,6 versus 27,5 ± 11,1 dias, respectivamente, p = 0,05). Uma maior prevalência dos sintomas de dismenorreia, dispareunia, dor pélvica crônica, infertilidade, alterações intestinais e urinárias foi observada no grupo casos comparado ao grupo controle. O tempo médio entre o início dos sintomas e o diagnóstico definitivo de endometriose foi de 5,2 ± 6,9 anos. Comparando os dois grupos, não foram observadas diferenças significativas nas frequências alélicas e genotípicas dos polimorfismos PGR +331C > T, CYP17A1 -34A > G e CYP19A1 1531G > A, e nem considerando os sintomas, a classificação e o estadiamento da endometriose. O genótipo combinado PGR +331TT/CYP17A1 -34AA/CYP19A11531AA está associado positivamente com a endometriose (razão de possibilidades [RP] = 1,72; intervalo de confiança de 95% [IC95%] = 1,09­2,72). Conclusões A análise combinada dos polimorfismos PGR-CYP17A1-CYP19A1 sugere uma interação gene-gene na susceptibilidade à endometriose. Estes resultados podem contribuir para a identificação de biomarcadores para o diagnóstico e/ou prognóstico da doença, assim como de possíveis alvos moleculares para um tratamento individualizado.

Combined Effect of the PGR + 331C > T, CYP17A1 -34A > G and CYP19A1 1531G > A Polymorphisms on the Risk of Developing Endometriosis / Efeito combinado dos polimorfismos PGR + 331C > T, CYP17A1 -34A > G e CYP19A1 1531G > A no risco de desenvolvimento da endometriose

Abstract Purpose To evaluate the magnitude of the association of the polymorphisms of the genes PGR, CYP17A1 and CYP19A1 in the development of endometriosis. Methods This is a retrospective case-control study involving 161 women with endometriosis (cases) and 179 controls. The polymorphisms were genotyped by real-time polymerase chain reaction using the TaqMan system. The association of the polymorphisms with endometriosis was evaluated using the multivariate logistic regression. Results The endometriosis patients were significantly younger than the controls (36.0±7.3 versus 38.0±8.5 respectively, p = 0.023), and they had a lower body mass index (26.3±4.8 versus 27.9±5.7 respectively, p = 0.006), higher average duration of the menstrual flow (7.4±4.9 versus 6.1±4.4 days respectively, p = 0.03), and lower average time intervals between menstrual periods (25.2±9.6 versus 27.5±11.1 days respectively, p = 0.05). A higher prevalence of symptoms of dysmenorrhea, dyspareunia, chronic pelvic pain, infertility and intestinal or urinary changes was observed in the case group when compared with the control group. The interval between the onset of symptoms and the definitive diagnosis of endometriosis was 5.2±6.9 years. When comparing both groups, significant differences were not observed in the allelic and genotypic frequencies of the polymorphisms PGR + 331C > T, CYP17A1 -34A > G and CYP19A1 1531G > A, even when considering the symptoms, classification and stage of the endometriosis. The combined genotype PGR + 331TT/CYP17A1 -34AA/CYP19A11531AA is positively associated with endometriosis (odds ratio [OR] = 1.72; 95% confidence interval [95%CI] = 1.09-2.72). Conclusions The combined analysis of the polymorphisms PGR-CYP17A1-CYP19A1 suggests a gene-gene interaction in the susceptibility to endometriosis. These results may contribute to the identification of biomarkers for the diagnosis and/or prognosis of the disease and of possible molecular targets for individualized treatments.

Resumo Objetivo Avaliar a magnitude de associação de polimorfismos nos genes PGR, CYP17A1 e CYP19A1 no desenvolvimento da endometriose. Métodos Este é um estudo retrospectivo do tipo caso-controle, envolvendo 161 mulheres com endometriose (casos) e 179 controles. Os polimorfismos foram genotipados pela reação em cadeia da polimerase em tempo real utilizando o sistema TaqMan. A associação dos polimorfismos estudados com a endometriose foi avaliada pela regressão logística multivariada. Resultados As pacientes com endometriose eram significativamente mais jovens do que os controles (36,0±7,3 versus 38,0±8,5, respectivamente, p = 0,023), apresentaram um índice de massa corporal menor (26,3±4,8 versus 27,9±5,7, respectivamente, p = 0,006), maior tempo médio de duração do fluxo menstrual (7,4±4,9 versus 6,1±4,4 dias, respectivamente, p = 0,03) e menor tempo médio do intervalo entre as menstruações (25,2±9,6 versus 27,5±11,1 dias, respectivamente, p = 0,05). Uma maior prevalência dos sintomas de dismenorreia, dispareunia, dor pélvica crônica, infertilidade, alterações intestinais e urinárias foi observada no grupo casos comparado ao grupo controle. O tempo médio entre o início dos sintomas e o diagnóstico definitivo de endometriose foi de 5,2±6,9 anos. Comparando os dois grupos, não foram observadas diferenças significativas nas frequências alélicas e genotípicas dos polimorfismos PGR + 331C > T, CYP17A1 -34A > G e CYP19A1 1531G > A, e nem considerando os sintomas, a classificação e o estadiamento da endometriose. O genótipo combinado PGR + 331TT/CYP17A1 -34AA/CYP19A11531AA está associado positivamente com a endometriose (razão de possibilidades [RP] = 1,72; intervalo de confiança de 95% [IC95%] = 1,09-2,72). Conclusões A análise combinada dos polimorfismos PGR-CYP17A1-CYP19A1 sugere uma interação gene-gene na susceptibilidade à endometriose. Estes resultados podem contribuir para a identificação de biomarcadores para o diagnóstico e/ou prognóstico da doença, assim como de possíveis alvos moleculares para um tratamento individualizado.

Combined effect of vascular endothelial growth factor and its receptor polymorphisms in endometriosis: a case-control study.

OBJECTIVE: Endometriosis is a multifactorial gynecological disease, whose pathogenesis is crucially dependent on angiogenesis, which is signaled via vascular endothelial growth factor (VEGF) and its receptor (VEGFR2). We hypothesize that single nucleotide polymorphisms (SNPs) in VEGF and VEGFR2 genes may influence the onset and/or the progression of endometriosis. The main aim of this study was to investigate the contribution of VEGF and VEGFR2 SNPs as risk factors for endometriosis, as well as their association with endometriosis symptoms. STUDY DESIGN: A case-control study was conducted, involving 293 endometriosis patients and 223 controls, who were submitted to laparoscopic or laparotomy surgery at hospitals from the Brazilian public health system. Genotyping of VEGF (-2578C>A, -460T>C, -1154G>A, +405G>C and +936C>T) and VEGFR2 (-604T>C, 1192C>T) SNPs was performed by TaqMan real-time polymerase chain reaction. The association between SNPs and endometriosis, deep infiltrating endometriosis (DIE) or endometriosis symptoms was estimated by odds ratios (OR) with their 95% confidence intervals (CI), which were calculated using multivariate logistic regression models. RESULTS: VEGF variant alleles -2578A and -1154A were associated with increased endometriosis risk (OR: 1.39, 95% CI: 1.04-1.87 and OR: 1.63, 95% CI: 1.12-2.37, respectively), whereas VEGF 405C and VEGFR2 1192T were associated with lower risk of endometriosis (OR: 0.66, 95% CI: 0.43-1.00 and OR: 0.58, 95% CI: 0.40-0.84, respectively). The combination of wild-type genotypes of both VEGF -2578C>A and -1154G>A with variant genotypes of both VEGF +405G>C and VEGFR2 1192C>T showed the best protective effect against the development of endometriosis, either considering all cases (OR: 0.33, 95% CI: 0.12-0.89) or only DIE (OR: 0.30, 95% CI: 0.10-0.87). The combination of variant genotypes of VEGF -2578C>A, -1154G>A, +405G>C and VEGFR2 1192C>T was also protective against DIE (OR: 0.67, 95% CI: 0.46-0.96). VEGFR2 1192C>T were associated with reduced cyclical urinary complaints (OR: 0.40, 95% CI: 0.18-0.88). CONCLUSIONS: Our results indicate that VEGF SNPs -2578C>A and -1154G>A increase endometriosis risk, whereas VEGF +405G>C and VEGFR2 1192C>T are protective against disease development, with VEGFR2 1192C>T also reducing cyclical urinary symptoms. The combined analysis of VEGF-VEGFR2 genotypes suggests a gene-gene interaction in endometriosis susceptibility.

Polymorphisms in VEGF and KDR genes in the development of endometriosis: a systematic review / Polimorfismos nos genes VEGF e KDR no desenvolvimento da endometriose: revisão sistemática

Abstract Objectives: to review studies that used case-control design to verify the association of polymorphisms in VEGF and KDR genes in the development of endometriosis. Methods: the systematic review selected articles published until September 1, 2015 from PubMed, MEDLINE, BVS, SciELO databases, considering the following key words: endometriosis and ("polymorphism" or "SNP" or "genetic polymorphism") and ("VEGF" OR "Vascular endothelial growth factor" or "VEGFR-2" or "Vascular endothelial growth factor-2" or "KDR" or "Kinase Insert Domain Receptor"). Results: 106 articles were identified, only 11 were eligible. Discrepant results were observed regarding polymorphisms in VEGF gene in the development of endometriosis, which can be explained by methodological differences, sample size, eligible control type, using the unadjusted risk estimates and the heterogeneity of the studied population. Only one study investigated polymorphisms in KDR gene in the development of endometriosis, however it was ineligible for this review. Conclusions: to avoid discrepancy in the results, we suggest that the ideal control group should be formed by fertile women and free of gynecological diseases. Multicentric studies with adequate design, involving different population besides the combined analysis on polymorphisms in VEGF and KDR genes are still necessary to contribute in the understanding of this disease, which are social, clinical and economical problems.

Resumo Objetivos: revisar os trabalhos que utilizaram o delineamento caso-controle para verificar a associação de polimorfismos nos genes VEGF e KDR no desenvolvimento da endometriose. Métodos: revisão sistemática que pesquisou nas bases de dados PubMed, MEDLINE, BVS, SciELO os artigos publicados até o dia 1 de setembro de 2015, considerando os descritores: endometriosis and ("polymorphism" or "SNP" or "geneticpolymorphism") and ("VEGF" or "Vascular endothelial growth factor" or "VEGFR-2" or "Vascular endothelial growth factor-2" or "KDR" or "Kinase Insert Domain Receptor"). Resultados: identificou-se 106 artigos, sendo 11 considerados elegíveis. Observou-se resultados discrepantes quanto aos polimorfismos no gene VEGF no desenvolvimento da endometriose, podendo ser explicados pelas diferenças metodológicas, pelo tamanho amostral, pelo tipo de controle elegível, pela utilização da estimativa de risco não ajustada e pela heterogeneidade das populações estudadas. Apenas um estudo investigou polimorfismos no gene KDR no desenvolvimento da endometriose, contudo não foi elegível nesta revisão. Conclusões: para evitar as discrepâncias dos resultados observados sugerimos que o grupo controle ideal deva ser formado por mulheres férteis e livres de doenças ginecológicas. Estudos multicêntricos com delineamento adequado, envolvendo diferentes populações, além da análise combinada de polimorfismos nos genes VEGF e KDR ainda são necessários para contribuir no entendimento desta doença que é um problema social, clínico e econômico.

Avaliação da influência dos polimorfismos no gene do fator decrescimento endotelial vascular e seu receptor na etiologia da endometriose / Polymorphisms influence the evaluation of the factor gene vascular endothelial growth and its receptor in the etiology of endometriosis

A endometriose é considerada uma doença complexa, influenciada tanto por fatores genéticos como ambientais. A angiogênese via sinalização do fator de crescimento endotelial vascular (VEGF) e do seu receptor de domínio de inserção da quinase (KDR), é um processo crucialno estabelecimento e progressão da endometriose. Polimorfismos de um único nucleotídeo (SNP) nos genes VEGF e KDR podem influenciar no desenvolvimento da doença. O presente estudo teve como objetivo avaliar o papel dos SNPs do VEGF (...) na etiologia da endometriose. A população do estudo foi composta por 293 mulheres com diagnóstico histopatologico de endometriose (casos) e 223 mulheres sem a evidência laparoscópica da doença (controle). A genotipagem dos SNPs estudados foi realizada pela técnica de reação em cadeia da polimerase (PCR) em tempo real utilizando o sistema TaqMan. (...) Verificou-se um efeito protetor dos haplótipos de VEGF (CTGC, ATGG e CCGG) e KDR (TTT e CTA) com a susceptibilidade da endometriose; e um risco aumentado dos haplótipos de VEGF (ACAG) e KDR (TCA e CCA)com o desenvolvimento da doença. Uma associação negativa foi encontrada nos genótipos combinados de VEGF e KDR com o desenvolvimento da endometriose e com a presença dos sintomas (dismenorreia, dor pélvica, dispareunia e sintomas urinários). Realizou-se também uma revisão sistemática, utilizando o sistema STROBE, sobre a associação dos SNPs de VEGF e KDR no desenvolvimento da endometriose, além de descrever as diferenças metodológicas dos estudos caso controle. Como conclusão os SNPs de VEGF e KDR estão associados com o desenvolvimento da endometriose e seus sintomas, sugerindo que a via de sinalização, VEGF-KDR, é um importante fator na etiologia da doença. Este estudo serve como base de dados para futuras aplicações que visem o desenvolvimento de biomarcadores para o diagnóstico e/ou prognóstico da endometriose.

Endometriosis is considered a complex diseases influenced by both genetic and environmental factors. The angiogenesis via signaling vascular endothelial growth factor (VEGF) and its kinase insert domain receptor (KDR), is a crucial process in the establishment and progressionof endometriosis. Single nucleotide polymorphisms (SNPs) in VEGF and KDR genes can influence the development of the disease. (...) SNPs in the etiology of endometriosis. The study population consisted of 293women with histopathological diagnosis of endometriosis (cases) and 223 women without laparoscopic evidence of disease (controls). Genotyping of the studied SNPs was performed by polymerase chain reaction (PCR) in real time using the TaqMan system. Logistic regression was used, being obtained odds ratios (OR) and confidence intervals (95 percent CI) to evaluate the associations of the studied SNPs and the development of endometriosis, and the presence of symptoms. (...) It was found a protective effect of VEGF (CTGC, ATGG and GGCC) and KDR (TTT and CTA) haplotypes susceptibility to endometriosis; and an increased risk of VEGF (ACAG) and KDR (CCA and TCA) haplotypes with the development of the disease. Negative association was found in the combined genotypes of VEGF and KDR withthe development of endometriosis and the presence of symptoms (dysmenorrhea, pelvic pain, dyspareunia and urinary symptoms). It was also carried out a systematic review using the STROBE system on the association of VEGF and KDR SNPs in the development of endometriosis, and describes the methodological differences of case-control studies. In conclusion VEGF and KDR SNPs are associated with the development of endometriosis and its symptoms, suggesting that signaling pathway, VEGF-KDR, is an important factor in theetiology of the disease. This study serves as a database for future applications for thedevelopment of biomarkers for the diagnosis and / or prognosis of endometriosis.

Role of vascular endothelial growth factor polymorphisms (-2578C>A, -460 T>C, -1154G>A, +405G>C and +936C>T) in endometriosis: a case-control study with Brazilians.

BACKGROUND: Endometriosis is regarded as a complex and heterogeneous disease in which genetic and environmental factors contribute to the phenotype. The Vascular Endothelial Growth Factor (VEGF) plays important roles in the pathogenesis of endometriosis. The present study was aimed at investigating the contribution of VEGF polymorphisms as risk factors for the development of endometriosis. This is the first study to evaluate the combined influence of the five most common VEGF polymorphisms. METHODS: This study was conducted at two hospitals from the Brazilian public health system, and comprised 294 women submitted to laparoscopic or laparotomy surgery: 182 patients had a histologically confirmed diagnosis of endometriosis (cases), whereas 112 had no evidence of the disease (controls). The VEGF polymorphisms were determined by TaqMan real-time polymerase chain reaction. The odds ratio (OR) with their 95% confidence intervals (CI) were calculated using an unconditional logistic regression model. RESULTS: Endometriosis patients and controls did not differ regarding age distribution, whereas the body mass index was significantly lower in endometriosis patients, when compared with controls (23.1 ± 3.9 versus 27.3 ± 5.9, P < 0.001). The evaluation of gynecological symptoms, including dysmenorrhea, non-cyclic chronic pelvic pain, dyspareunia and infertility, indicates significantly higher prevalences among endometriosis cases. The variant allele -1154A was significantly associated with endometriosis, either considering all cases (OR: 1.90, 95% CI: 1.23-2.97), deep infiltrating endometriosis (DIE) (OR: 1.83, 95% CI: 1.16-2.90) or moderate and severe endometriosis (stages III-IV) (OR: 1.97, 95% CI: 1.21-3.19). No significant differences were found in allele or genotype distributions of the -2578C > A, -460 T > C, +405G > C and +936C > T polymorphisms between endometriosis cases and controls. A total of six haplotypes were inferred derived from four polymorphisms (-2578C > A, -460 T > C, -1154G > A and +405G > C). There was a protective association between CCGG haplotype and endometriosis, either considering all cases (OR: 0.36, 95% CI: 0.15-0.86), DIE (OR: 0.37 95% CI: 0.15 - 0.90) or stages III-IV (OR: 0.35 95% CI: 0.13 - 0.95). CONCLUSIONS: The present results indicate a positive association between VEGF -1154G > A and the risk of developing endometriosis, whereas the CCGG haplotype may be protective against the development of disease.