Smoking intensity and bladder cancer aggressiveness at diagnosis.

OBJECTIVE: To explore the relation between cigarette smoking intensity and bladder cancer aggressiveness at first diagnosis. METHODS: Patients diagnosed with urinary bladder cancer (BC) between 1995-2011 under the age of 75 years were retrospectively identified from the Netherlands Cancer Registry and invited for a study on genetic and lifestyle risk factors for BC. Information on patients' self-reported smoking history was retrieved by means of a postal questionnaire. Tumors were stratified regarding the risk of progression defined by tumor stage and grade. Multinomial logistic regression was used to analyze the relation between smoking intensity and aggressiveness of the tumor. RESULTS: The UBC study population comprised 323 (17.4%) never smokers, 870 (46.8%) former cigarette smokers, and 630 (33.9%) current cigarette smokers. A higher smoking amount was a risk factor of getting high-risk non-muscle invasive bladder cancer (NMIBC) compared with low-risk NMIBC in ever and former cigarette smokers (OR: 1.02 per cigarette smoked, 95% CI: 1.00-1.03 and OR: 1.03, 95% CI: 1.01-1.05, respectively). A statistically significant dose-response increase in the risk of a more aggressive cancer type (high-risk NMIBC and MIBC) was observed with increasing smoking duration among former smokers (p for trend 0.035 and 0.008, respectively). No significant association of the evaluated smoking intensity variables was observed in current smokers. A longer time of smoking cessation correlated with a lower odds of a more aggressive cancer. CONCLUSION: We observed a weak increase in the risk of a more aggressive tumor type with increasing smoking intensity in former smokers, but this association was absent in current smokers. This conflicting result may suggest that there is no strong relation between smoking intensity and bladder cancer aggressiveness. Analyses of prospective studies with longitudinal smoking assessment may provide a more definitive answer to the research question.

Polymorphisms in stromal genes and susceptibility to serous epithelial ovarian cancer: a report from the Ovarian Cancer Association Consortium.

Alterations in stromal tissue components can inhibit or promote epithelial tumorigenesis. Decorin (DCN) and lumican (LUM) show reduced stromal expression in serous epithelial ovarian cancer (sEOC). We hypothesized that common variants in these genes associate with risk. Associations with sEOC among Caucasians were estimated with odds ratios (OR) among 397 cases and 920 controls in two U.S.-based studies (discovery set), 436 cases and 1,098 controls in Australia (replication set 1) and a consortium of 15 studies comprising 1,668 cases and 4,249 controls (replication set 2). The discovery set and replication set 1 (833 cases and 2,013 controls) showed statistically homogeneous (P(heterogeneity)≥0.48) decreased risks of sEOC at four variants: DCN rs3138165, rs13312816 and rs516115, and LUM rs17018765 (OR = 0.6 to 0.9; P(trend) = 0.001 to 0.03). Results from replication set 2 were statistically homogeneous (P(heterogeneity)≥0.13) and associated with increased risks at DCN rs3138165 and rs13312816, and LUM rs17018765: all ORs = 1.2; P(trend)≤0.02. The ORs at the four variants were statistically heterogeneous across all 18 studies (P(heterogeneity)≤0.03), which precluded combining. In post-hoc analyses, interactions were observed between each variant and recruitment period (P(interaction)≤0.003), age at diagnosis (P(interaction) = 0.04), and year of diagnosis (P(interaction) = 0.05) in the five studies with available information (1,044 cases, 2,469 controls). We conclude that variants in DCN and LUM are not directly associated with sEOC, and that confirmation of possible effect modification of the variants by non-genetic factors is required.

Common variants in DGKK are strongly associated with risk of hypospadias.

Hypospadias is a common congenital malformation of the male external genitalia. We performed a genome-wide association study using pooled DNA from 436 individuals with hypospadias (cases) and 494 controls of European descent and selected the highest ranked SNPs for individual genotyping in the discovery sample, an additional Dutch sample of 133 cases and their parents, and a Swedish series of 266 cases and 402 controls. Individual genotyping of two SNPs (rs1934179 and rs7063116) in DGKK, encoding diacylglycerol kinase κ, produced compelling evidence for association with hypospadias in the discovery sample (allele-specific odds ratio (OR) = 2.5, P = 2.5 × 10⁻¹¹ and OR = 2.3, P = 2.9 × 10⁻9, respectively) and in the Dutch (OR = 3.9, P = 2.4 × 10⁻5 and OR = 3.8, P = 3.4 × 10⁻5) and Swedish (OR = 2.5, P = 2.6 × 10⁻8 and OR = 2.2, P = 2.7 × 10⁻6) replication samples. Expression studies showed expression of DGKK in preputial tissue of cases and controls, which was lower in carriers of the risk allele of rs1934179 (P = 0.047). We propose DGKK as a major risk gene for hypospadias.

Genetics of hypospadias: are single-nucleotide polymorphisms in SRD5A2, ESR1, ESR2, and ATF3 really associated with the malformation?

CONTEXT: Hypospadias is a common congenital malformation of the male external genitalia with a multifactorial etiology. Little is known about the genes involved in hypospadias. A few genetic associations have been reported but mainly in studies of small sample size. Most of these associations have not been replicated. OBJECTIVE: The aim of this study was to investigate whether previously reported associations for four single-nucleotide polymorphisms (SNPs) in genes involved in hormonal pathways could be replicated in a large Dutch hypospadias sample. The SNPs investigated are rs523349 in steroid-5 alpha-reductase (SRD5A2), rs6932902 in estrogen receptor 1 (ESR1), rs2987983 in ESR2, and rs11119982 in activating transcription factor 3 (ATF3). DESIGN, PARTICIPANTS, AND METHODS: We genotyped 620 Caucasian hypospadias cases and 596 controls for these SNPs using TaqMan-based genotyping. RESULTS: We did not replicate the associations of the SNPs in SRD5A2 and ESR1 with hypospadias. The SNPs in ESR2 and ATF3 were borderline associated with hypospadias [odds ratios 0.9 (95% confidence interval 0.7-1.0) and 1.2 (95% confidence interval 1.0-1.4), respectively] but in the opposite direction compared with earlier publications. Stratification according to localization of the urethral opening produced comparable results in the subgroups. CONCLUSIONS: The lack of consistency between our and previously performed studies might represent spurious results or chance findings in our or the earlier studies, differences in criteria used to select the study populations, or a real difference between populations, i.e. different genes contributing to disease risk. These results once again confirm the importance of replication in genetic association approaches.

Genome-wide association study identifies 19p13.3 (UNC13A) and 9p21.2 as susceptibility loci for sporadic amyotrophic lateral sclerosis.

We conducted a genome-wide association study among 2,323 individuals with sporadic amyotrophic lateral sclerosis (ALS) and 9,013 control subjects and evaluated all SNPs with P < 1.0 x 10(-4) in a second, independent cohort of 2,532 affected individuals and 5,940 controls. Analysis of the genome-wide data revealed genome-wide significance for one SNP, rs12608932, with P = 1.30 x 10(-9). This SNP showed robust replication in the second cohort (P = 1.86 x 10(-6)), and a combined analysis over the two stages yielded P = 2.53 x 10(-14). The rs12608932 SNP is located at 19p13.3 and maps to a haplotype block within the boundaries of UNC13A, which regulates the release of neurotransmitters such as glutamate at neuromuscular synapses. Follow-up of additional SNPs showed genome-wide significance for two further SNPs (rs2814707, with P = 7.45 x 10(-9), and rs3849942, with P = 1.01 x 10(-8)) in the combined analysis of both stages. These SNPs are located at chromosome 9p21.2, in a linkage region for familial ALS with frontotemporal dementia found previously in several large pedigrees.

An association study of 45 folate-related genes in spina bifida: Involvement of cubilin (CUBN) and tRNA aspartic acid methyltransferase 1 (TRDMT1).

BACKGROUND: Spina bifida is a class of neural tube defects, which are congenital malformations of the central nervous system with a prevalence of 0.5 to 12 per 1000 births globally. In this article we attempt to identify genes related to folate and its metabolic pathways that are involved in the etiology of spina bifida. METHODS: We selected 50 folate metabolism-related genes and genotyped polymorphisms in those genes. Eighty-seven polymorphisms in 45 genes passed quality controls. Associations with spina bifida were investigated in 180 patients and 190 controls. For those polymorphisms that were nominally associated with spina bifida risk, the relation with serum and red blood cell folate, vitamin B(12), and homocysteine was evaluated in controls. RESULTS: A polymorphism in CUBN was significantly associated with decreased spina bifida risk, after correction for multiple testing, and was related to increased vitamin B(12) (p = 0.039) and red blood cell folate (p = 0.001). The CUBN gene encodes the intrinsic factor-cobalamin receptor (or cubilin), a peripheral membrane protein that acts as a receptor for intrinsic factor-vitamin B(12) complexes. Vitamin B(12) is an important cofactor in the folate metabolism, and low B(12) status in mothers has been linked to neural tube defects in children. Other interesting findings include nominally significant associations with polymorphisms in TRDMT1, ALDH1L1, SARDH, and SLCA19A1 (RFC1). CONCLUSION: Our study indicates interesting new candidate genes and functional pathways for further study and confirms earlier findings. None of the genes CUBN, TRDMT1, ALDH1L1, or SARDH have been investigated previously for association with spina bifida.

Polymorphisms in the H19 gene and the risk of bladder cancer.

OBJECTIVES: H19 is an imprinted gene coding for an oncofetal RNA that is down-regulated postnatally. Reactivation of the H19 gene has been observed in bladder tumors, and H19 expression has been associated with early recurrence of disease. In this study we examined whether sequence variants within the H19 gene are associated with the risk of developing bladder cancer. METHODS: Five tagging single nucleotide polymorphisms (tagSNPs) covering the H19 gene and its promoter region were selected with the use of Haploview software. One hundred and seventy-seven bladder cancer patients who were referred to our university hospital were genotyped for these tagSNPs. The genotypes were compared with those of a random sample of 204 controls of the general population. RESULTS: A significantly decreased risk of bladder cancer was found for the rs2839698 TC genotype (odds ratio [OR], 0.60; 95% confidence interval (95%CI), 0.36-0.99), but not for CC homozygotes. The rs2839698 TC genotype was especially associated with a reduced risk of developing non-muscle-invasive disease (OR, 0.52; 95%CI, 0.28-0.94). Borderline significantly decreased risks of bladder cancer were found for the rs2107425 CT genotype (OR, 0.66; 95%CI, 0.43-1.00), but not for TT homozygotes or for T allele carriers of rs217727 (OR, 0.74; 95%CI, 0.51-1.06). Haplotype analysis did not result in stronger associations with bladder cancer compared with the single-locus analyses. CONCLUSIONS: An SNP polymorphism in the non-protein-encoding H19 gene is associated with a decreased risk of developing non-muscle-invasive bladder cancer. This association was found for only heterozygotes, not for homozygotes.

Catechol-O-methyltransferase genotype is associated with plasma total homocysteine levels and may increase venous thrombosis risk.

A disturbed methylation has been proposed as a mechanism via which homocysteine is associated with diseases like vascular disease, neural tube defects and mental disorders. Catechol-O-methyltransferase (COMT) is involved in the S-adenosylmethionine-dependent methylation of catecholamines and catecholestrogens and in this way contributes to homocysteine synthesis. COMT dysfunction has been related to schizophrenia and breast cancer. We hypothesized that COMT dysfunction by virtue of functional genetic polymorphisms may affect plasma total homocysteine (tHcy). Our primary objective was to study the association between common COMT polymorphisms and tHcy. Secondly, we evaluated these polymorphisms as a risk factor for recurrent venous thrombosis. We obtained genotype data from four polymorphisms in the COMT gene (rs2097603, rs4633, rs4680 [324G>A] and rs174699) from 401 population-based controls. We performed haplotype analysis to investigate the association between common haplotypes and tHcy. In addition, we assessed the rs4680 variant as a genetic risk factor in a case-control study on recurrent venous thrombosis (n = 169). We identified a common haplotype that was significantly associated with tHcy levels. This effect was largely explained by the rs4680 variant, resulting in an increase in tHcy of 10.4% (95% CI 0.01 to 0.21, p = 0.03) for 324AA compared with 324GG subjects. Interestingly, we found that the 324AA genotype was more common in venous thrombosis patients (OR 1.61 [95% CI 0.97 to 2.65], p = 0.06) compared to control subjects. We show that the COMT rs4680 variant modulates tHcy, and might be associated with venous thrombosis risk as well.

The methionine synthase reductase 66A>G polymorphism is a maternal risk factor for spina bifida.

The methionine synthase reductase (MTRR) enzyme restores methionine synthase (MTR) enzyme activity and therefore plays an essential role in homocysteine remethylation. In some studies, the 66A>G polymorphism in the MTRR gene was associated with increased neural tube defect (NTD) risk. Using a case-control design, we studied the association between the MTRR 66A>G polymorphism and spina bifida risk in 121 mothers, 109 spina bifida patients, 292 control women, and 234 pediatric controls. Possible interactions between the MTRR 66A>G variant and the MTR 2756A>G polymorphism, the MTHFR 677C>T variant, plasma vitamin B12, and plasma methylmalonic acid (MMA) levels were examined in the 121 mothers and 292 control women. Meta-analyses were conducted to set the results of the case-control study in the context of eligible literature on the relation between the MTRR 66A>G variant and NTD risk. Finally, a transmission disequilibrium test was performed for 82 complete mother-father-child triads to test for preferential transmission of the MTRR risk allele. In our case-control study, the MTRR 66A>G polymorphism had no influence on spina bifida risk in children [odds ratio (OR) 0.6, 95% confidence interval (CI) 0.4-1.1]. The MTRR 66GG genotype increased maternal spina bifida risk by 2.1-fold (OR 2.1, 95% CI 1.3-3.3). This risk became more pronounced in combination with the MTHFR 677TT genotype (OR 4.0, 95% CI 1.3-12.5). Moreover, we demonstrate a possible interaction between the MTRR 66GG genotype and high plasma MMA levels (OR 5.5, 95% CI 2.2-13.5). The meta-analyses demonstrated that the maternal MTRR 66GG genotype was associated with an overall 55% (95% CI 1.04-2.30) increase in NTD risk and that the MTRR 66GG genotype did not increase NTD risk in children (OR 0.96, 95% CI 0.46-2.01). These data show that the MTRR 66GG genotype is a maternal risk factor for spina bifida especially when intracellular vitamin B12 status is low.

Maternal MTHFR 677C>T is a risk factor for congenital heart defects: effect modification by periconceptional folate supplementation.

AIMS: Periconceptional folate supplementation prevents neural tube defects and possibly congenital heart defects (CHD) as well. The search for candidate genes involved in the folate metabolism includes the methylenetetrahydrofolate reductase (MTHFR) 677C > T polymorphism. We studied the association between MTHFR 677C > T variants and CHD risk. The interaction with periconceptional folate supplementation was also investigated. METHODS AND RESULTS: A case-control study and a family-based transmission disequilibrium test (TDT) were conducted to explore this association. In 133 triads, the TDT revealed no association of the fetal 677T allele with the development of a heart defect. In 158 mothers with a CHD-affected child, the maternal MTHFR 677CT and TT genotypes in combination with no use of periconceptional folate supplements were associated with, respectively, a three-fold (OR 3.3 95% CI 1.46-7.32) and six-fold (OR 6.3 95% CI 2.32-17.27) increased risk for conotruncal heart defects in offspring. In a case-only study, the interaction between periconceptional folate supplementation and maternal MTHFR genotype was significant (P = 0.012). CONCLUSION: The maternal MTHFR 677C > T variants are a risk factor for CHD in offspring, confined to conotruncal heart defects. A gene-environment interaction between maternal MTFHR 677CT and TT genotypes with periconceptional folate supplementation was observed. These findings provide a mechanism of the protective role of folate and support the thesis that periconceptional folate supplementation might prevent CHD.

Correlation of rheumatoid arthritis severity with the genetic functional variants and circulating levels of macrophage migration inhibitory factor.

OBJECTIVE: To study whether genetic variants of macrophage migration inhibitory factor (MIF), the MIF -173G>C and CATT(5-8) alleles, are associated with disease severity and levels of circulating MIF in patients with rheumatoid arthritis (RA). METHODS: Genotyping was performed in patients with early RA and in healthy controls. Demographic data, disease activity, and outcome measurements were compared between patients with and without the MIF variants. MIF -173G>C and CATT(5-8) polymorphisms were genotyped, and a newly developed enzyme-linked immunosorbent assay for human MIF was used. Allele and genotype distributions of the MIF -173G>C and CATT(5-8) polymorphisms were compared between patients and controls by chi-square test. Multiple regression analysis was performed to assess the independence of the MIF functional genetic variants as risk factors for radiologic joint damage. RESULTS: Genotyping of the -173G>C and CATT(5-8) polymorphisms of MIF in RA patients and healthy individuals (n = 277 each) revealed similar frequencies of genotypes and haplotypes in both groups. No significant differences in demographic or clinical features were observed between RA patients carrying the MIF -173C allele or the MIF CATT7 allele or both and non-carrier RA patients. Radiologic joint damage was significantly higher in patients carrying risk alleles of the MIF -173G>C or the MIF CATT(5-8) functional variants. No synergistic effects between both genetic variants were observed. Multivariate regression analysis revealed that presence of the MIF -173C/C and MIF CATT(7/7) genotypes and having 1 MIF -173C allele were independent prognostic variables. Carriership of the MIF -173C allele (P = 0.002) or MIF CATT7 allele (P = 0.004) was associated with significantly higher circulating MIF levels compared with those in subjects having none of the risk-conferring alleles, and greater circulating MIF levels correlated with more severe radiologic joint damage (r = 0.64, P = 0.001). CONCLUSION: The MIF polymorphisms are not associated with RA susceptibility but are associated with high levels of radiologic joint damage. High circulating MIF levels were shown to correlate strongly with radiologic joint damage, suggesting that MIF expression is genetically determined and can be used as a novel prognostic tool in RA.