Genome-wide association study of right-sided colonic diverticulosis in a Korean population.

Diverticulosis results from complex interactions related to aging, environmental factors and genetic predisposition. Despite epidemiologic evidence of genetic risk factors, there has been no attempt to identify genes that confer susceptibility to colonic diverticulosis. We performed the first genome-wide association study (GWAS) on susceptibility to diverticulosis in a Korean population. A GWAS was carried out in 7,948 healthy individuals: 893 patients and 1,075 controls comprised the test set, and 346 patients and 305 controls comprised the replication set. Diverticulosis was diagnosed by colonoscopy during comprehensive medical check-ups, and single-nucleotide polymorphisms (SNPs) related to diverticulosis were detected with the Affymetrix Axiom KORV1.1-96 Array. In all, 9 SNPs were identified in three SNP aggregates in the test set (P < 10-3, within 200 kb) after adjusting for sex. All the SNPs were replicated in the replication set (P < 0.05). Three SNPs were near the WNT4 gene, four near the RHOU gene, and two in the OAS1/3 genes. The top SNP associated with right-sided colonic diverticulosis was rs22538787, located near the WNT4 gene [combined set, P-value = 3.128 × 10-6, odds ratio = 1.415 (95% confidence interval: 1.223-1.637)]. These 9 novel SNP alleles associated with the WNT4, RHOU, and OAS1/3 genes are possibly involved in the underlying genetic susceptibility to right-sided diverticulosis. Our results provide basic knowledge about the development of diverticulosis in an Asian population.

Genome-Wide Analysis Reveals Four Novel Loci for Attention-Deficit Hyperactivity Disorder in Korean Youths.

OBJECTIVES: The molecular mechanisms underlying attention-deficit hyperactivity disorder (ADHD) remain unclear. Therefore, this study aimed to identify the genetic susceptibility loci for ADHD in Korean children with ADHD. We performed a case-control and a family-based genome-wide association study (GWAS), as well as genome-wide quantitative trait locus (QTL) analyses, for two symptom traits. METHODS: A total of 135 subjects (71 cases and 64 controls), for the case-control analysis, and 54 subjects (27 probands and 27 unaffected siblings), for the family-based analysis, were included. RESULTS: The genome-wide QTL analysis identified four single nucleotide polymorphisms (SNPs) (rs7684645 near APELA, rs12538843 near YAE1D1 and POU6F2, rs11074258 near MCTP2, and rs34396552 near CIDEA) that were significantly associated with the number of inattention symptoms in ADHD. These SNPs showed possible association with ADHD in the family-based GWAS, and with hyperactivity-impulsivity in genome-wide QTL analyses. Moreover, association signals in the family-based QTL analysis for the number of inattention symptoms were clustered near genes IL10, IL19, SCL5A9, and SKINTL. CONCLUSION: We have identified four QTLs with genome-wide significance and several promising candidates that could potentially be associated with ADHD (CXCR4, UPF1, SETD5, NALCN-AS1, ERC1, SOX2-OT, FGFR2, ANO4, and TBL1XR1). Further replication studies with larger sample sizes are needed.

Bilirubin and Stroke Risk Using a Mendelian Randomization Design.

BACKGROUND AND PURPOSE: Circulating bilirubin, a natural antioxidant, is associated with decreased risk of stroke. However, the nature of the relationship between the two remains unknown. We used a Mendelian randomization analysis to assess the causal effect of serum bilirubin on stroke risk in Koreans. METHODS: The 14 single-nucleotide polymorphisms (SNPs) (<10-7) including rs6742078 of uridine diphosphoglucuronyl-transferase were selected from genome-wide association study of bilirubin level in the KCPS-II (Korean Cancer Prevention Study-II) Biobank subcohort consisting of 4793 healthy Korean and 806 stroke cases. Weighted genetic risk score was calculated using 14 SNPs selected from the top SNPs. RESULTS: Both rs6742078 (F statistics=138) and weighted genetic risk score with 14 SNPs (F statistics=187) were strongly associated with bilirubin levels. Simultaneously, serum bilirubin level was associated with decreased risk of stroke in an ordinary least-squares analysis. However, in 2-stage least-squares Mendelian randomization analysis, no causal relationship between serum bilirubin and stroke risk was found. CONCLUSIONS: There is no evidence that bilirubin level is causally associated with risk of stroke in Koreans. Therefore, bilirubin level is not a risk determinant of stroke.

Set up of cutoff thresholds for kinship determination using SNP loci.

The usefulness of single nucleotide polymorphism (SNP) loci for kinship testing has been demonstrated in many case works, and suggested as a promising marker for relationship identification. For interpreting results based on the calculation of the likelihood ratio (LR) in kinship testing, it is important to prepare cutoffs for respective relatives which are dependent on genetic relatedness. For this, analysis using true pedigree data is significant and reliable as it reflects the actual frequencies of markers in the population. In this study, the kinship index was explored through 1209 parent-child pairs, 1373 full sibling pairs, and 247 uncle-nephew pairs using 136 SNP loci. The cutoffs for LR were set up using different numbers of SNP loci with accuracy, sensitivity, and specificity. It is expected that this study can support the application of SNP loci-based kinship testing for various relationships.

Identification of genetic susceptibility loci for intestinal Behçet's disease.

Several recent genome-wide association studies (GWAS) identified susceptibility loci/genes for Behçet's disease (BD). However, no study has specifically investigated the genetic susceptibility loci associated with intestinal involvement in BD. We aimed to identify distinctive genetic susceptibility loci/genes associated with intestinal involvement in BD and determine their roles in intestinal inflammation as well as their interactions with genes involved in inflammatory bowel disease (IBD). GWAS and validation studies showed intestinal BD-specific associations with an NAALADL2 gene locus (rs3914501, P = 3.8 × 10-4) and a YIPF7 gene locus (rs6838327, P = 3.5 × 10-4). Validation, haplotype, and pathway analyses showed distinct genetic architectures between intestinal BD and BD without intestinal involvement. Furthermore, network analysis revealed shared pathogenic pathways between intestinal BD and IBD. Gene functional analyses indicated that down-regulation of NAALADL2 and YIPF7 expression was associated with exacerbating intestinal inflammatory responses both in vitro and in vivo. Our results provide new insights into intestinal BD-specific genetic variations, which represents a distinct pathway from BD without intestinal involvement. Functional consequences of the intestinal BD-specific NAALADL2 and YIPF7 expression patterns proved a suggestive association with intestinal inflammation risk, which warrants further validation.

Association between Polymorphisms in Bitter Taste Receptor Genes and Clinical Features in Korean Asthmatics.

BACKGROUND: Bitter taste receptors (TAS2R) in human airway smooth muscle have recently been shown to have an important role in bronchodilation, together with ß2-adrenergic receptors. OBJECT: To evaluate the association between genetic variations in TAS2R and clinical features, including bronchodilator response and asthma control. METHOD: We analyzed the association between single nucleotide polymorphisms (SNPs) of TAS2R10 and TAS2R14 and variables such as demographic data, atopy, duration of disease, and asthma control status, including variables such as asthma control test (ACT) score, percent predicted value of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio, as well as bronchodilator response (BDR), in 721 asthma patients in Korea. RESULT: Three novel SNPs of 633G>A, 645C>A, and -79G>A in TAS2R10 and 3 known SNPs of -815T>C, -1267G>A, and -1897T>C in TAS2R14 were analyzed. Increased BDR was significantly associated with SNPs of -815T>C [OR (95% CI) = 1.88 (1.01-3.49), p = 0.04 ] [J Gen Physiol 2005;125:535-553; Am J Respir Cell Mol Biol 2010;42:373-3812], -1267A>G [OR (95% CI) = 2.07 (1.03-4.15), p = 0.04] and -1897T>C [OR (95% CI) = 3.05 (1.01-9.23), p = 0.04, in a dominant model, and OR = 1.91 (1.08-3.36), p = 0.02, in a codominant model] of the TAS2R14 gene. There was a significant association between -815T>C and a low mean ACT score [OR (95% CI) = 5.84 (1.94-17.61), p = 0.001]. In haplotype analysis, TAC, CAT, and TGT, or TG and CA haplotypes on TAS2R14 were significantly associated with increased BDR; CAT and CA haplotypes were significantly associated with a low ACT score. CONCLUSION: Genetic variations in TAS2Rs may be valuable genetic markers to predict therapeutic response and outcomes in asthma. Further research in an independent cohort is needed.

Tumor Necrosis Factor-Alpha Gene Polymorphism Associated With Development of Hepatitis B Virus-associated Hepatocellular Carcinoma.

GOAL AND BACKGROUND: Host genetic diversity may play roles in development of HCC. This study was conducted to validate the effects of tumor necrosis factor-alpha (TNF-α) gene polymorphism on development of hepatocellular carcinoma (HCC) in patients chronically infected with hepatitis B virus (HBV). STUDY: The study cohort comprised 224 patients with HBV-associated HCC and 206 with HBV-associated liver cirrhosis (LC). Using chromosomal DNA, TNF-α promoter gene polymorphisms were determined at 3 common single-nucleotide polymorphism (SNP) sites (TNF-α-1031 T>C, TNF-α-857 C>T, and TNF-α-308 G>A) using a single base extension method. The genotype distributions were compared between the 2 groups. All the HBV-associated LC patients were followed up regularly every 6 to 12 months for surveillance of HCC development. RESULTS: In the cross-sectional analysis, the frequency of TNF-α-857 T allele was much higher in patients with HCC compared with those with LC (42% vs. 31%, P<0.01). Of 206 HBV-associated LC patients, 12 (5.8%) developed HCC during the median follow-up period of 36 months. The cumulative occurrence rates of HCC were significantly higher in patients with TNF-α-857 T allele than those withTNF-α-857 C/C genotype (1-, 3-, and 5-y rates: 2.9%, 12.8%, and 20.7% vs. 0%, 3.1%, and 5.3%, respectively; P=0.013). However, the other genetic polymorphisms of TNF-α promoter gene did not affect the development of HCC. In multivariate analysis, TNF-α-857 T allele was a significant predictor of HCC development (hazard ratio 6.29, P=0.01). CONCLUSION: Our data suggest that TNF-α-857 T allele is closely associated with development of HCC in HBV-associated LC patients.

The SNP rs3128965 of HLA-DPB1 as a genetic marker of the AERD phenotype.

BACKGROUND: Two common clinical syndromes of acetylsalicylic acid (aspirin) hypersensitivity, aspirin-exacerbated respiratory disease (AERD) and aspirin-exacerbated cutaneous disease (AECD), were subjected to a genome-wide association study to identify strong genetic markers for aspirin hypersensitivity in a Korean population. METHODS: A comparison of SNP genotype frequencies on an Affymetrix Genome-Wide Human SNP array of 179 AERD patients and 1989 healthy normal control subjects (NC) revealed SNPs on chromosome 6 that were associated with AERD, but not AECD. To validate the association, we enrolled a second cohort comprising AERD (n = 264), NC (n = 238) and disease-control (aspirin tolerant asthma; ATA, n = 387) groups. RESULTS: The minor genotype frequency (AG or AA) of a particular SNP, rs3128965, in the HLA-DPB1 region was higher in the AERD group compared to the ATA or NC group (P = 0.001, P = 0.002, in a co-dominant analysis model, respectively). Comparison of rs3128965 alleles with the clinical features of asthmatics revealed that patients harboring the A allele had increased bronchial hyperresponsiveness to inhaled aspirin and methacholine, and higher 15-HETE levels, than those without the A allele (P = 0.039, 0.037, and 0.004, respectively). CONCLUSIONS: This implies the potential of rs3128965 as a genetic marker for diagnosis and prediction of the AERD phenotype.

Common and rare variants in the exons and regulatory regions of osteoporosis-related genes improve osteoporotic fracture risk prediction.

CONTEXT: Osteoporotic fracture risk is highly heritable, but genome-wide association studies have explained only a small proportion of the heritability to date. Genetic data may improve prediction of fracture risk in osteopenic subjects and assist early intervention and management. OBJECTIVE: To detect common and rare variants in coding and regulatory regions related to osteoporosis-related traits, and to investigate whether genetic profiling improves the prediction of fracture risk. DESIGN AND SETTING: This cross-sectional study was conducted in three clinical units in Korea. PARTICIPANTS: Postmenopausal women with extreme phenotypes (n = 982) were used for the discovery set, and 3895 participants were used for the replication set. MAIN OUTCOME MEASURE: We performed targeted resequencing of 198 genes. Genetic risk scores from common variants (GRS-C) and from common and rare variants (GRS-T) were calculated. RESULTS: Nineteen common variants in 17 genes (of the discovered 34 functional variants in 26 genes) and 31 rare variants in five genes (of the discovered 87 functional variants in 15 genes) were associated with one or more osteoporosis-related traits. Accuracy of fracture risk classification was improved in the osteopenic patients by adding GRS-C to fracture risk assessment models (6.8%; P < .001) and was further improved by adding GRS-T (9.6%; P < .001). GRS-C improved classification accuracy for vertebral and nonvertebral fractures by 7.3% (P = .005) and 3.0% (P = .091), and GRS-T further improved accuracy by 10.2% (P < .001) and 4.9% (P = .008), respectively. CONCLUSIONS: Our results suggest that both common and rare functional variants may contribute to osteoporotic fracture and that adding genetic profiling data to current models could improve the prediction of fracture risk in an osteopenic individual.

The Interaction Between Allelic Variants of CD86 and CD40LG: A Common Risk Factor of Allergic Asthma and Rheumatoid Arthritis.

PURPOSE: Allergic asthma (AA) and rheumatoid arthritis (RA) are immune tolerance-related diseases, and immune tolerance is known to be influenced by costimulatory molecules. In this study, we sought to identify common genetic susceptibility in AA and RA. METHODS: Two hundred cases of AA, 184 cases of RA, and 182 healthy controls were recruited at the Seoul National University Hospital, Seoul, Korea. Eight single nucleotide polymorphisms (SNPs) in five genes coding costimulatory molecules, namely, -318C>T, +49A>G, and 6230G>A in CTLA4, IVS3+17T>C in CD28, -3479T>G and I179V in CD86, -1C>T in CD40, and -3458A>G in CD40LG were scored, and genetic interactions were evaluated by multifactor dimensionality reduction (MDR) analysis. RESULTS: MDR analysis revealed a significant gene-gene interaction between -3479T>G CD86 and -3458A>G CD40LG for AA. Subjects with the T/T genotype of -3479T>G CD86 and the A/A genotype of -3458A>G CD40LG were found to be significantly more likely to develop AA than those with the T/T genotype of -3479T>G CD86 and A/- genotype of -3458A>G CD40LG (adjusted OR, 6.09; 95% CI, 2.89-12.98; logistic regression analysis controlled by age). Similarly those subjects showed a significant risk of developing RA (adjusted OR, 39.35; 95% CI, 15.01-107.00, logistic regression analysis controlled by age). CONCLUSIONS: Our findings suggest that a genetic interaction between CD86 and CD40LG favors the development of both AA and RA.

Genetic factors associated with response to intravitreal ranibizumab in Korean patients with neovascular age-related macular degeneration.

PURPOSE: To investigate the association between genetic risk variants for age-related macular degeneration (AMD) and response to intravitreal ranibizumab in Korean patients with neovascular AMD. METHODS: This prospective study included 273 treatment-naive patients (273 eyes) who underwent 5 monthly injections (Months 0, 1, 2, 3, and 4) of intravitreal ranibizumab for neovascular AMD. Patients were genotyped for 23 single-nucleotide polymorphisms within 12 AMD-relevant genes. For each polymorphism, genotypic association with good response at Month 5, predetermined as visual improvement of ≥ 8 Early Treatment Diabetic Retinopathy Study letters from baseline, was investigated with logistic regression analysis adjusted for age, gender, smoking, baseline Early Treatment Diabetic Retinopathy Study letter, central retinal thickness, lesion area, and type of choroidal neovascularization. RESULTS: At Month 5, visual acuity improved by 9.1 ± 17.6 letters from baseline, and 136 patients (49.8%) were classified as good responders. In logistic regression, no tested polymorphism showed statistically significant association with favorable visual outcome at Month 5. When unadjusted for multiple tests, AA genotype for VEGF rs699947 had an increased chance of good response compared with other genotypes (odds ratio, 3.61; 95% confidence interval, 1.42-9.18; P = 0.0071). CONCLUSION: In this Korean neovascular AMD cohort, there was no statistically significant effect of genotype on early visual outcome after ranibizumab treatment.

Prognostic impact of telomere maintenance gene polymorphisms on hepatocellular carcinoma patients with chronic hepatitis B.

UNLABELLED: Our goal was to determine whether single-nucleotide polymorphisms (SNPs) of telomere maintenance genes influence the development and clinical outcomes of patients with hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). We evaluated 20 SNPs of five telomere maintenance genes in 702 patients with HCC and 351 hepatitis B virus surface antigen-positive controls without HCC. Significant SNPs were then validated in an independent cohort of 857 HCC patients and 429 controls. We assessed the association of each SNP with the development of HCC and overall survival through a multivariate Cox proportional analysis. A significantly increased risk of HCC development was identified for the telomerase-associated protein 1 (TEP1) rs1713449 SNP in both the discovery and replication phases (combined odds ratio = 1.42, P = 9.378 × 10(-5) ). In addition, the TEP1 rs1713449, TEP1 rs872072, protection of telomeres 1 homolog rs7784168, telomerase reverse transcriptase rs13167280, and telomeric repeat binding factor 1 rs2306494 SNPs had a significant effect on the overall survival, and a similar survival effect was validated in the replication cohort. Moreover, there was a significant dose-dependent association between the number of putatively high-risk genotypes of the five aforementioned SNPs and overall survival. The median survival time was significantly prolonged for patients with HCC with two or fewer putatively high-risk genotypes versus those with three or more high-risk genotypes (85 versus 44 months, log-rank P = 4.483 × 10(-5) ), and this was demonstrated in the replication cohort (52 versus 37 months, log-rank P = 0.026). CONCLUSION: These observations suggest that the SNPs of telomere maintenance genes play a potential role in the development of HCC and the survival of HCC patients with chronic HBV infections.

Genome-wide genotype-based risk model for survival in acute myeloid leukaemia patients with normal karyotype.

Single nucleotide polymorphisms (SNP) are inter-individual genetic variations that could explain inter-individual differences of response/survival to chemotherapy. The present study was performed to build up a risk model for survival in 247 patients with acute myeloid leukaemia (AML) with normal karyotype (AML-NK). Genome-wide Affymetrix SNP array 6.0 was used for genotyping in discovery set (n = 118). After identifying significant SNPs for overall survival (OS) in single SNP analysis, a risk model was constructed. Out of 632 957 autosomal SNPs analysed, finally four SNPs (rs2826063, rs12791420, rs11623492 and rs2575369) were introduced into the risk model. The model could stratify the patients according to their OS in discovery set (P = 1·053656 × 10−4). Replication was performed using Sequenom platform for genotyping in the validation cohort (n = 129). The model incorporated with clinical and four SNP risk score was successfully replicated in a validation set (P = 5·38206 × 10−3). The integration of four SNPs and clinical factors into the risk model showed higher area under the curve (AUC) reults than in the model incorporating only clinical or only four SNPs, suggesting improved prognostic stratification power by combination of four SNPs and clinical factors. In conclusion, a genome-wide SNP-based risk model in 247 patients with AML-NK can identify a group of high risk patients with poor survival.

Genetic variants in the IL12B gene are associated with inflammatory bowel diseases in the Korean population.

BACKGROUND AND AIM: Recent genomic studies have identified genetic variants in the IL12B gene, which encodes the p40 subunit shared by interleukin 12 and interleukin 23, as susceptibility loci for inflammatory bowel disease (IBD). The study aimed to identify additional novel genetic variants in IL12B and investigated whether variants confer susceptibility to the development of Crohn's disease (CD) or ulcerative colitis (UC) in the Korean population. METHODS: To detect single nucleotide polymorphisms (SNPs) in IL12B, direct sequencing of all coding exons, exon-intron boundaries, promoter region, and 5' untranslated region was performed in 24 randomly selected samples. Selected haplotype-tagging SNPs were subsequently genotyped in 493 IBD patients (245 patients with CD and 248 with UC) and 504 healthy controls. RESULTS: Two haplotype-tagging SNPs (rs2288831 and rs919766) were selected through direct sequencing and were genotyped. Of them, SNP rs2288831 in the IL12B gene was significantly associated with CD susceptibility in allelic association analysis (odds ratio = 1.30; 95% confidence interval 1.04-1.62; P = 0.019). This significant association with CD was also observed for a haplotype consisting of SNP rs919766 and rs2288831 (odds ratio = 1.29; 95% confidence interval 1.03-1.60; P = 0.025). However, none of IL12B SNPs were associated with UC susceptibility. Finally, no specific associations between genetic variants and disease phenotype of CD were identified. CONCLUSIONS: This study is first to identify SNP rs2288831 in the IL12B gene as a susceptible variation for CD. Further studies in other ethnic groups are warranted to validate the association of this genetic variant with IBD.

Single nucleotide polymorphism in the FLT4 gene is associated with atopic dermatitis in Koreans.

BACKGROUND: The histology of atopic dermatitis includes dilated, tortuous vessels within the papillary dermis and perivascular edema. METHOD: This study included 1120 case-control samples (646 AD patients and 474 normal controls), for which we genotyped 34 SNPs from four VEGF family genes and the FLT4 gene. For the rs11607007 SNP in the VEGFB gene and three SNPs (rs10085109, rs3736062, and rs11949194) in the FLT4 gene, which had significant p-values in the initial stage, were further investigated using 1132 independent samples (440 AD patients and 692 normal controls). RESULT: Of the four SNPs, rs10085109 in the FLT4 gene was only significantly associated with the AD phenotype in both initial and replication samples. Although no SNPs in the VEGFA gene were significantly associated with AD, the rs2010963 SNP had a marginally significant effect on log-eosinophil counts. CONCLUSION: The rs10085109 SNP in the FLT4 gene were associated with susceptibility to AD.

Genetic predisposition of hand-foot skin reaction after sorafenib therapy in patients with hepatocellular carcinoma.

BACKGROUND: Sorafenib currently sets the new standard for advanced hepatocellular carcinoma (HCC). It has been suggested that Asian patients with HCC have increased susceptibility to hand-foot skin reaction (HFSR) related to sorafenib therapy. The authors investigated the association between sorafenib-induced HFSR and genetic polymorphisms in Korean patients with HCC. METHODS: For this prospective cohort study, the authors enrolled 59 consecutive patients with intermediate stage HCC from 5 centers in Korea. All patients received sorafenib 400 mg twice daily in combination with transarterial chemoembolization (TACE). Genotyping was performed on a total of 49 single nucleotide polymorphisms (SNPs) in 8 candidate genes (minor allelic frequency ≥5%). Serum levels of vascular endothelial growth factor (VEGF) and tumor necrosis factor-alpha (TNF-α) were measured using enzyme-linked immunosorbent assays before therapy and 1 month after therapy. RESULTS: During a median treatment period of 18 months, 55 patients (93%) developed sorafenib-induced HFSR, including grade 1 reactions in 15 patients, grade 2 reactions in 27 patients, and grade 3 reaction in 13 patients. The SNPs TNF-α -308GG, VEGF -94GG, VEGF 1991CC, VEGF IVS3-28CC, and uridine diphosphate glucuronosyltransferase 1 family-polypeptide A9 (UGT1A9) IVS1-37431AA were associated significantly with the development of high-grade (grade 2 or 3) HFSR in univariate analysis (P < .05). In multivariate analysis, the SNPs VEGF 1991CC (odds ratio, 45.7), TNF-α -308GG (odds ratio, 44.1), and UGT1A9 IVS1-37431AA (odds ratio, 18.7) were identified as independent risk factors for the development of high-grade HFSR (P = .01, P = .02, and P = .02, respectively). He serum TNF-α level measured 1 month after sorafenib therapy was correlated significantly with the development of high-grade HFSR (odds ratio, 3.56; P = .026). CONCLUSIONS: Differences in the incidence of HFSR may have been caused by ethnic differences in genetic polymorphisms of the TNF-α, VEGF, and UGT1A9 genes, especially in relation to the expression of serum TNF-α after sorafenib therapy.

Lack of association of genetic variations of deoxycytidine kinase with toxicity or survival of non-small-cell lung cancer patients treated with gemcitabine plus cisplatin.

The aim of this study was to determine whether tagging polymorphisms (tSNPs) of deoxycytidine kinase (DCK) have an effect on toxicity or prognosis in patients with non-small-cell lung cancer (NSCLC) treated with gemcitabine plus cisplatin. Three tSNPs (-201 C>T, rs2306744; IVS2+9846 G>A, rs12648166; IVS6+1392 T>C, rs4694362) were chosen using the international HapMap Project and Japanese Single-Nucleotide Polymorphisms. We evaluated the associations of the tSNPs with hematologic toxicity or overall survival of 139 NSCLC patients at stages IIIA/IIIB (59) and IV (80). Hematologic toxicity such as neutropenia, thrombocytopenia, and anemia were not different by the three tSNPs or haplotypes (CGT, CAT, and CAC) of DCK. The genetic variations did not affect survival of the patients (log-rank p: 0.248 for -201 C>T, 0.571 for IVS2+9846 G>A, 0.686 for IVS6+1392 T>C, 0.556 for CGT, 0.453 for CAT, and 0.845 for CAC). In a Cox model, these tSNPs and haplotypes did not reveal prognostic relevance (aHR and 95% CI: 0.954 and 0.611 to 1.489 for -201 C>T; 1.193 and 0.719 to 1.979 for IVS2+9846 G>A; 1.072 and 0.674 to 1.706 for IVS6+1392 T>C, 0,668 and 0.205 to 2.175 for CGT, 1.043 and 0.713 to 1.525 for CAT, and 1.043 and 0.701 to 1.550 for CAC). This is the first study to focus on the association of tSNPs and their haplotypes of DCK with toxicity and survival in NSCLC patients. This suggests that genetic variations of DCK have no effect on the outcomes in the patients treated with gemcitabine-based chemotherapy.

Association of CYP2C19*2 and *3 genetic variants with essential hypertension in Koreans.

PURPOSE: The cytochrome P450 2C19 (CYP2C19) metabolizes arachidonic acid to produce epoxyicosanoid acids, which are involved in vascular tone and regulation of blood pressure. Recent findings suggest that CYP2C19 gene might be considered as a novel candidate gene for treatment of cardiovascular disease. The aim of the present study was to evaluate the association between two variants, CYP2C19* 2 (681G>A) and CYP2C19*3 (636G>A) and the development of essential hypertension (EH) in Koreans. MATERIALS AND METHODS: We carried out an association study in a total of 1190 individuals (527 hypertensive subjects and 663 unrelated healthy controls). The CYP2C19 polymorphisms were genotyped using the SNaPShot™ assay. RESULTS: The distribution of alleles and genotypes of CYP2C19* 3 showed significant difference between hypertensive patients and normal controls (p=0.011 and p=0.013, respectively). Logistic regression analysis indicated that the CYP2C19*3 (636A) allele carriers were significantly associated with EH [odds ratio, 0.691; 95% confidence interval (CI), 0.512-0.932, p=0.016], in comparison to wild type homozygotes (CYP2C19*1/*1). Neither genotype nor allele distribution of CYP2C19*2 polymorphism showed significant differences between hypertensive and control groups (p>0.05). CONCLUSION: Our present findings strengthen the evidence of an association between CYP2C19 gene polymorphism and EH prevalence. In particular, the CYP2C19*3 defective allele may contribute to reduced risk for the development of EH.

Polymorphisms of DNA repair genes in Korean hepatocellular carcinoma patients with chronic hepatitis B: possible implications on survival.

BACKGROUND & AIMS: We aimed at determining whether single nucleotide polymorphisms (SNPs) of DNA repair genes influence the development and clinical outcomes of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). METHODS: We evaluated 14 SNPs of eight DNA repair genes in 708 patients with HCC and 388 HBsAg positive controls without HCC. The Kaplan-Meier methods with log-rank test and Cox regression models were used to compare survival of HCC patients according to the genotype. RESULTS: The SNP of XRCC4 rs1805377 was significantly associated with decreased risk of HCC development (OR, 0.592; p=0.028) and improved overall survival of patients with HCC (median survival time (MST) of 48, 72, and 89 months for the AA, AG, and GG genotypes, respectively; p=0.044). In addition, SNP of OGG1 rs1053133 was significantly associated with postoperative recurrence (OR, 0.604; p=0.049), tumor differentiation (OR, 0.571; p=0.041), and improved survival of resected HCC (MST of 55 and 108 months for the GG and GC/CC genotypes, p=0.001). The multivariate analysis showed that OGG1 rs1052133, XRCC1 rs25487, ERCC5 rs2018836, ERCC5 rs3818356, and XRCC4 rs1805377 had a significant effect on survival. Moreover, a strong dose-dependent association was observed between the number of putative high-risk genotypes of OGG1, XRCC1, ERCC5, and XRCC4 with the overall survival. The MST of HCC with ≥2 putative high-risk genotypes was significantly prolonged compared to those with ≥3 high-risk genotypes (76 vs. 46 months, respectively, p=0.002). CONCLUSIONS: Polymorphisms of DNA repair genes play a potential role in the development, progression, and survival of Korean HCC patients with chronic HBV infection.