• Title/Summary/Keyword: Genetic risk assessment

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MLH1 Polymorphisms and Cancer risk: a Meta-analysis Based on 33 Case-control Studies

  • Xu, Jia-Li;Yin, Zhi-Qiang;Huang, Ming-De;Wang, Xie-Feng;Gao, Wen;Liu, Ling-Xiang;Wang, Rong-Sheng;Huang, Pu-Wen;Yin, Yong-Mei;Liu, Ping;Shu, Yong-Qian
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.3
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    • pp.901-907
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    • 2012
  • Objective: Cumulative evidence suggests that MLH1, the key component in the mismatch pathway, plays an important role in human cancers. Two potential functional polymorphisms (-93G>A and I219V) of MLH1 have been implicated in cancer risk. The aim of this meta-analysis was to summarize the evidence for associations. Methods: Eligible studies were identified by searching the electronic literature PubMed, ScienceDirect and Embase databases for relevant reports and bibliographies. Studies were included if of case-control design investigating MLH1 polymorphisms (-93G>A and I219V) and cancer risk with sufficient raw data for analysis. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to evaluate the strength of associations. Results: Our meta-analysis from 33 published case-control studies showed the variant A allele of -93G>A polymorphism to be associated with increased risk in all genetic models (AA vs. GG: OR = 1.22, 95% CI: 1.03-1.44), especially among non-Asians (AA vs. GG: OR = 1.28, 95% CI: 1.04-1.58). For the I219V polymorphism, however, there was no main effect associated with overall cancer risk in any genetic model. Conclusions: The meta-analysis suggested that the MLH1 -93G>A polymorphism may be a biomarker of cancer susceptibility. Large sample association studies and assessment of gene-to-gene as well as gene-to-environment interactions are required to confirm these findings.

A Case of Molecular Diagnosis of Ornithine Transcarbamylase Deficiency (분자 유전학적 검사로 진단된 Ornithine Transcarbamylase Deficiency 1 예)

  • Lee, Eun-Sil
    • Journal of Yeungnam Medical Science
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    • v.24 no.2
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    • pp.322-328
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    • 2007
  • Ornithine transcarbamylase (OTC) deficiency is the most common inborn error of urea cycle metabolism; it is inherited in an X-linked manner. The OTC catalyzes the third step of the urea cycle, the conversion of ornithine and carbamyl phosphate to citrulline. Deficiency of OTC leads to the accumulation of ammonia, causing neurological deficits. In most affected hemizygote males, OTC deficiency manifests as hyperammonemic coma that often leads to death in the newborn period, and those who recover from the coma may be neurologically impaired due to the sequelae of the hyperammonemic encephalopathy. In some, late-onset manifestations develop. We report a male neonate with early onset OT deficiency that had apnea and was comatous. On mutation analysis using DNA sequencing after polymerase chain reaction (PCR) amplification of the 10 exons, deletions of 10 bases in codon 285, causing a frame shift was detected in exon 8. The mother and a sister were diagnosed as female carriers. Therefore, genetic counseling and the risk assessment could be provided to the family.

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Quantitative Approaches to Assess Key Carcinogenic Events of Genotoxic Carcinogens

  • Fukushima, Shoji;Gi, Min;Fujioka, Masaki;Kakehashi, Anna;Wanibuchi, Hideki;Matsumoto, Michiharu
    • Toxicological Research
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    • v.34 no.4
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    • pp.291-296
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    • 2018
  • Chemical carcinogenesis is a multistep process. Genotoxic carcinogens, which are DNA-reactive, induce DNA adduct formation and genetic alterations in target cells, thereby generating mutated cells (initiation). Subsequently, preneoplastic lesions appear through clonal proliferation of the mutated cells and transform into tumors (promotion and progression). Many factors may influence these processes in a dose-dependent manner. Therefore, quantitative analysis plays an important role in studies on the carcinogenic threshold of genotoxic carcinogens. Herein, we present data on the relationship between key carcinogenic events and their deriving point of departure (PoD). Their PoDs were also compared to those of the carcinogenesis pathway. In an experiment, the liver of rats exposed to 2-amino-3,8-dimethylimidazo-(4,5-f)quinoxaline (MeIQx) was examined to determine the formation of MeIQx-DNA adducts, generation of mutations at LacI transgene, and induction of preneoplastic glutathione S-transferase placental form (GST-P)-positive foci and tumors (benign and malignant). The PoDs of the above key events in the carcinogenicity of MeIQx were increased as the carcinogenesis advanced; however, these PoDs were lower than those of tumor induction. Thus, the order of key events during tumor induction in the liver was as follows: formation of DNA adducts ${\ll}$ Mutations ${\ll}$ GST-positive foci (preneoplasia) ${\ll}$ Tumor (adenoma and carcinoma). We also obtained similar data on the genotoxic and carcinogenic PoDs of other hepatocarcinogens, such as 2-amino-3,8-dimethylimidazo(4,5-f)quinoline. These results contribute to elucidating the existence of a genotoxic and carcinogenic threshold.

Molecular evolutionary analysis reveals Arctic-like rabies viruses evolved and dispersed independently in North and South Asia

  • Yu, Xin;Zhu, Hongwei;Bo, Yongheng;Li, Youzhi;Zhang, Jianlong;Jiang, Linlin;Chen, Guozhong;Zhang, Xingxiao;Wen, Yongjun
    • Journal of Veterinary Science
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    • v.22 no.1
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    • pp.5.1-5.16
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    • 2021
  • Background: Arctic-like (AL) lineages of rabies viruses (RABVs) remains endemic in some Arctic and Asia countries. However, their evolutionary dynamics are largely unappreciated. Objectives: We attempted to estimate the evolutionary history, geographic origin and spread of the Arctic-related RABVs. Methods: Full length or partial sequences of the N and G genes were used to infer the evolutionary aspects of AL RABVs by Bayesian evolutionary analysis. Results: The most recent common ancestor (tMRCA) of the current Arctic and AL RABVs emerged in the 1830s and evolved independently after diversification. Population demographic analysis indicated that the viruses experienced gradual growth followed by a sudden decrease in its population size from the mid-1980s to approximately 2000. Genetic flow patterns among the regions reveal a high geographic correlation in AL RABVs transmission. Discrete phylogeography suggests that the geographic origin of the AL RABVs was in east Russia in approximately the 1830s. The ancestral AL RABV then diversified and immigrated to the countries in Northeast Asia, while the viruses in South Asia were dispersed to the neighboring regions from India. The N and G genes of RABVs in both clades sustained high levels of purifying selection, and the positive selection sites were mainly found on the C-terminus of the G gene. Conclusions: The current AL RABVs circulating in South and North Asia evolved and dispersed independently.

Association between the XRCC1 Arg194Trp Polymorphism and Glioma Risk: an Updated Meta-analysis

  • Xu, Cheng;Chen, Pin;Liu, Wei;Gu, Ai-Hua;Wang, Xin-Ru
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7419-7424
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    • 2014
  • Gliomas are the most common type of primary brain tumors. The XRCC1 Arg194Trp variant affects the proliferating cell nuclear antigen(PCNA) binding region, which suggests that this mutation may contribute to gliomagenesis and a number of articles have examine the association between XRCC1 Arg194Trp and the susceptibility to glioma. However, the results were conflicting. Test of heterogeneity, sensitivity analysis, meta-analysis, and assessment of publication bias were all performed in our present meta-analysis, covering a total of 5,407 patients and 7,715 healthy persons. In the overall analysis the XRCC1 Arg194Trp polymorphism showed a significant association with glioma susceptibility in a recessive mode l(for TrpTrp vs ArgArg+ArgTrp: OR=1.918, 95%CI=1.575-2.336, $I^2$=2.3%). In addition, analysis of subgroups presented an increased risk in Asians and populations-based on hospitals. The results suggested that the XRCC1 Arg194Trp polymorphism is a genetic risk factor for glioma, especially in Asian population. To further evaluate gene-gene and gene-environment interactions on XRCC1 polymorphisms and glioma risk, thousands of subjects and tissue-specific biochemical characterizations are required.

The Genetic Variations of RETNLB Gene are Associated with Serum Levels of Alkaline Phosphatase in the Korean Population

  • Ahn, Hyo-Jun;Eom, Yong-Bin
    • Biomedical Science Letters
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    • v.19 no.4
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    • pp.338-343
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    • 2013
  • Serum levels of alkaline phosphatase (ALP) are widely used in the clinical diagnosis of hepatic diseases and the assessment of liver status. They also have epidemiological significance to be prospective risk factors for bone diseases, such as osteitis deformans, rickets, osteomalacia, hyperparathyroidism, healing fractures, and osteoblastic bone tumors. In the previous study, single nucleotide polymorphisms (SNPs) in several genes have been reported to be associated with serum levels of liver enzyme in American population. We aimed to confirm whether the genetic variation of RETNLB (resistin like beta) gene also influence the serum levels of liver enzyme in Korean population. We genotyped variants in or near RETNLB in a population-based sample including 994 Korean adults. Here, we performed association analysis to elucidate the possible relations of genetic polymorphisms in RETNLB gene with serum levels of liver enzyme. By examining genotype data of a total of 944 subjects in 5 hospital health promotion centers, we discovered the RETNLB gene polymorphisms are associated with serum levels of ALP. The common and highest significant polymorphism was rs736327 (${\beta}$=8.66, P=2.37E-05), rs7639070 (${\beta}$=8.56, P=3.24E-05) with ALP in all groups. Furthermore, the ALP was consistently associated with rs736327 (${\beta}$=10.40, P=5.23E-05), rs7639070 (${\beta}$=10.32, P=6.74E-05) in the male population. Consequently, we found statistically significant SNPs in RETNLB gene that are associated with serum levels of ALP. In addition, these results suggest that the individuals with the minor alleles of the SNP in the RETNLB gene may have elevated serum levels of ALP in the Korean population.

Increased Methylation of Interleukin 6 Gene Is Associated with Obesity in Korean Women

  • Na, Yeon Kyung;Hong, Hae Sook;Lee, Won Kee;Kim, Young Hun;Kim, Dong Sun
    • Molecules and Cells
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    • v.38 no.5
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    • pp.452-456
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    • 2015
  • Obesity is the fifth leading risk for death globally, and a significant challenge to global health. It is a common, complex, non-malignant disease and develops due to interactions between the genes and the environment. DNA methylation can act as a downstream effector of environmental signals; analysis of this process therefore holds substantial promise for identifying mechanisms through which genetic and environmental factors jointly contribute to disease risk. To assess the effects of excessive weight and obesity on gene-specific methylation levels of promoter regions, we determined the methylation status of four genes involved in inflammation and oxidative stress [interleukin 6 (IL6), tumor necrosis factor ${\alpha}$ ($TNF{\alpha}$), mitochondrial transcription factor A (TFAM), and glucose transport 4 (GLUT4)] in blood cell-derived DNA from healthy women volunteers with a range of body mass indices (BMIs) by methylation-specific PCR. Interestingly, the samples from obese individuals ($BMI{\geq}30kg/m^2$) showed significantly increased hypermethylation for IL6 gene compared to normal weight ($BMI<23kg/m^2$) and overweight sample ($23kg/m^2{\leq}BMI<30kg/m^2$) (P = 0.034 and P = 0.026). However there was no statistically significant difference in promoter methylation of the other 3 genes between each group. These findings suggest that aberrant DNA methylation of IL6 gene promoter may play an important role in the etiology and pathogenesis of obesity and IL6 methylation could be used as molecular biomarker for obesity risk assessment. Further studies are required to elucidate the potential mechanisms underlying this relationship.

Comparison of Dietary Behavior between Atopic Dermatitis Patients and Controls in Elementary School Students Living in the Sung-nam Area (성남시 소재 초등학교 저학년에서 아토피 피부염 환자군과 대조군의 식생활 비교)

  • Shin, You-Kyung;Kim, Myung-Hee;Chung, Ja-Yong
    • Journal of the Korean Society of Food Culture
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    • v.23 no.5
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    • pp.655-661
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    • 2008
  • The prevalence of atopic dermatitis (AD) in children has increased dramatically in recent years. Although AD has genetic determinants, this rapid increase is most likely due to changes in environmental influences--for example, dietary changes. The purpose of this case-control study was to assess the relationship between the risk of developing AD and dietary factors, including eating habits, food intake, and the consumption of various functional foods in children at ages of 7 or 8 years. 143 AD patients and 335 healthy children participated in this study. A mini-dietary assessment was utilized to evaluate the food intake and dietary patterns of the children, and other information, including demographic and socioeconomic characteristics, eating habits, and the frequency of functional food use was collected using a questionnaire. The results demonstrated that, among the demographic and socioeconomic factors assessed in this study, female gender, mother's employment, and the family history of AD significantly increased the risk of AD. However, no differences in dietary habits and specific food intake between AD patients and healthy controls were identified. On the other hand, the frequencies of taking multivitamin supplements, Spirulina, or gamma-linoleic acid were significantly higher in AD patients than in the controls. These data indicate that alterations in eating habits and the intake of certain foods may not be a critical cause associated with the risk of AD in school-age children, and caution should be taken in recommending food elimination diets for the purpose of preventing AD. Further studies are required in order to determine whether the intake of specific nutrients could contribute to the increase or prevention of the development of AD in school-age children.

Environmental Monitoring of Herbicide Tolerant Genetically Modified Zoysiagrass (Zoysia japonica) around Confined Field Trials (제초제저항성 유전자변형 들잔디의 시험 격리포장 주변 환경방출 모니터링)

  • Lee, Bumkyu;Park, Kee Woong;Kim, Chang-Gi;Kang, Hong-Gyu;Sun, Hyeon-Jin;Kwon, Yong-Ik;Song, In-Ja;Ryu, Tae-Hun;Lee, Hyo-Yeon
    • Weed & Turfgrass Science
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    • v.3 no.4
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    • pp.305-311
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    • 2014
  • The cultivation area and use of genetically modified (GM) crops have been increased continuously over the world. Seed distribution and transgenes to environmental ecosystem is one of the most important factors in risk assessment and risk management of GM crop. Safe management for the development and commercialization of GM crops is required according to The Act on Transboundary Movements of Living Modified Organisms,etc (LMO Act) in Korea. This study was conducted to setup the environmental monitoring system of GM zoysiagrass (event JG21 and JG21-MS). The monitoring was performed in 4 GMO confined fields, Sungwhan, Ochang, Jeju University and Jeju Namwon. In the result of monitoring, we could not found any gene flow and distribution of GM zoysiagrass in the 3 fields, but one spill of JG21 was found in the Namwon field in 2012. These results suggest that continuous monitoring is necessary to detect the occurrence of GM zoysiagrass for preventing genetic contamination in natural environment.

Biological and Genetic Characterization of Cryptosporidium spp. and Giardia duodenalis Isolates from Five Hydrographical Basins in Northern Portugal

  • Almeida, Andre;Moreira, Maria Joao;Soares, Sonia;Delgado, Maria De Lurdes;Figueiredo, Joao;Silva, Elisabete;Castro, Antonio;Da Costa, Alexandra Viana;Da Costa, Jose Manuel Correia
    • Parasites, Hosts and Diseases
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    • v.48 no.2
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    • pp.105-111
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    • 2010
  • To understand the situation of water contamination with Cryptosporidium spp. and Giardia spp. in the northern region of Portugal, we have established a long-term program aimed at pinpointing the sources of surface water and environmental contamination, working with the water-supply industry. Here, we describe the results obtained with raw water samples collected in rivers of the 5 hydrographical basins. A total of 283 samples were analyzed using the Method 1623 EPA, USA. Genetic characterization was performed by PCR and sequencing of genes 18S rRNA of Cryptosporidium spp. and $\beta$-giardin of Giardia spp. Infectious stages of the protozoa were detected in 72.8% (206 of 283) of the water samples, with 15.2% (43 of 283) positive for Giardia duodenalis cysts, 9.5% (27 of 283) positive for Cryptosporidium spp. oocysts, and 48.1% (136 of 283) samples positive for both parasites. The most common zoonotic species found were G. duodenalis assemblages A-I, A-II, B, and E genotypes, and Cryptosporidium parvum, Cryptosporidium andersoni, Cryptosporidium hominis, and Cryptosporidium muris. These results suggest that cryptosporidiosis and giardiasis are important public health issues in northern Portugal. To the authors' knowledge, this is the first report evaluating the concentration of environmental stages of Cryptosporidium and Giardia in raw water samples in the northern region of Portugal.