Genetic evidence for ubiquitin-specific proteases USP24 and USP40 as candidate genes for late-onset Parkinson disease

Linkage studies have defined susceptibility regions for late-onset Parkinson disease (PD) on chromosomes 1 and 2, but specific genetic variants have not been definitively identified. Here we report the results of a case-control study to identify disease-associated single nucleotide polymorphisms (SNPs) in these loci. In the initial phase of our study, we genotyped two putative functional SNPs in ubiquitin-specific protease 24 (USP24), a biological candidate gene within the chromosome 1 linkage region, and scanned the chromosome 2 linkage peak with 43 SNPs in a sample set of 224 PD cases and 186 matched controls. Both USP24 SNPs were significantly associated with disease risk (p = 0.0037 for rs1165222:T > C, p.Thr195ILe, and p = 0.037 for rs13312:C > G, a SNP in the 3'-untranslated region), and one marker, rs1048603:C > T, p.Arg1123Cys, in USP40 was significant from the chromosome 2 scan (p = 0.038). Further genotyping of the region surrounding these initial markers led us to identify 19 additional SNPs with strong disease association. In the second phase, we genotyped the 22 significant markers in an additional 110 cases and 162 controls, which together with part of the initial sample set (201 cases and 149 controls) constitute an expanded sample set of 311 age- and gender-matched case-control pairs. Twenty-one markers were significant in the expanded sample set (most significant allelic p-value: 0.0006 for rs287235:C > G on chromosome 1, and 0.005 for rs838552:T > C on chromosome 2), and six SNPs in USP24 remained significant after conservatively adjusting for testing 27 markers (pBonferroni = 0.017-0.049). It is unlikely that population stratification contributed to this finding, as population stratification was undetectable in our sample set using 78 null markers. Our data suggest that genetic variants in USP24 and USP40 affect the risk for late-onset PD, which is consistent with the predicted role of the ubiquitination pathway in PD etiology.     

Association between PARK16 and Parkinson's disease in the Han Chinese population: a meta-analysis

PARK16 was reported to alter the risk for Parkinson's disease (PD) in the Japanese population. However, its role in Han Chinese PD patients has not been well established. Herein, we investigated the effect of 4 single-nucleotide polymorphisms (SNPs) within the PARK16 locus, including rs823128, rs947211, rs823156, and rs11240572, on the risk of PD by genotyping 497 Taiwanese patients with PD and 500 age-matched control subjects. The results were then meta-analyzed with available genetic association studies in the same population. The meta-analysis showed that PD patients demonstrated a lower frequency of the rs823128 G allele (11.93%) than control subjects (14.04%; odds ratio [OR] 0.83, 95% confidence interval [CI] 0.72–0.96, p = 0.010). The frequency of the rs947211 A allele (40.35%) in PD patients was lower than in control subjects (43.01%; OR 0.90, 95% CI 0.80–0.99, p = 0.047). The rs823156 G allele was less frequently seen in PD patients (17.32%) than in control subjects (21.35%; OR 0.77, 95% CI 0.69–0.86, p < 0.001). A lower frequency of the rs11240572 A allele was found in PD patients (14.01%) than in control subjects (17.66%; OR 0.76, 95% CI 0.66–0.88, p < 0.001). Our results indicate a robust protective effect of PARK16 in Han Chinese PD patients. Functional approaches are needed to elucidate the effects of these SNPs on the regulation of gene expression.     

Genome-wide association study confirms extant PD risk loci among the Dutch

In view of the population-specific heterogeneity in reported genetic risk factors for Parkinson's disease (PD), we conducted a genome-wide association study (GWAS) in a large sample of PD cases and controls from the Netherlands. After quality control (QC), a total of 514,799 SNPs genotyped in 772 PD cases and 2024 controls were included in our analyses. Direct replication of SNPs within SNCA and BST1 confirmed these two genes to be associated with PD in the Netherlands (SNCA, rs2736990: P = 1.63 × 10(-5), OR = 1.325 and BST1, rs12502586: P = 1.63 × 10(-3), OR = 1.337). Within SNCA, two independent signals in two different linkage disequilibrium (LD) blocks in the 3' and 5' ends of the gene were detected. Besides, post-hoc analysis confirmed GAK/DGKQ, HLA and MAPT as PD risk loci among the Dutch (GAK/DGKQ, rs2242235: P = 1.22 × 10(-4), OR = 1.51; HLA, rs4248166: P = 4.39 × 10(-5), OR = 1.36; and MAPT, rs3785880: P = 1.9 × 10(-3), OR = 1.19).     

Phactr2 and Parkinson's disease

Attempts at replicating the first genome-wide association study (GWAS) in Parkinson's disease (PD) have not successfully identified genetic risk factors. The present study reevaluates data from the first GWAS and focuses on the SNP (rs11155313, located in the Phactr2 gene) with the lowest P-value in the Tier 2 patient-control series. We employed four case-control series to examine the nominated SNP rs11155313 and identified association in US (OR: 1.39, P = 0.032), Canadian (OR: 1.41, P = 0.014) and Irish (OR: 1.44, P = 0.034) patient-control series, but not in the Norwegian series (OR: 1.15, P = 0.27). When combining all four series the observed trend was statistically significant (OR: 1.30, P < 0.001). This study shows that reappraisal of publicly available results of GWAS may help nominate new risk factors for PD.     

SNCA和PARK16多态性与中国辽宁地区汉族帕金森病人的关联分析

目的: 探究SNCA基因rs3857059和PARK16基因rs16856139单核苷酸多态性(SNPs)的频率分布及与帕金森病的关联性。方法: 本研究以214名中国辽宁地区汉族健康个体和213名帕金森病患者为研究对象,借助多重PCR及单一的限制性内切酶消化后的限制性片段长度多态性(RFLP)分析技术,对上述2种帕金森病易感基因中的2个SNPs位点进行等位基因多态性调查,并将所得的对照及病例组数据进行相关统计分析。结果: 多重PCR-RFLP法成功地检测出2个SNPs位点的所有基因型。基因频率数据显示rs3857059位点的G等位基因频率在帕金森病患者组高于对照组,差异有统计学意义(χ²=7.592,P<0.01,OR= 0.677,95% CI=0.517~0.888);rs16856139位点的T等位基因频率在帕金森病患者组低于对照组,差异有统计学意义(χ²=11.511,P< 0.01,OR= 0.390, 95% CI=0.227~0.669),这些结果提示本研究调查的2个SNPs构成了帕金森病患病的危险因素。结论: 帕金森病易感基因SNCA的rs3857059和PARK16的rs16856139位点基因频率分布在中国辽宁地区汉族群体中与帕金森病相关。     

Mitochondrial translation initiation factor 3 polymorphism and Parkinson's disease

Mitochondrial dysfunction has been proposed to play a role in the pathogenesis of Parkinson's disease (PD). Supportive of this hypothesis, several genetic variants that regulate mitochondrial function and homeostasis have been described to alter PD susceptibility. A recent report demonstrated association of a single nucleotide polymorphism in the mitochondrial translation initiation factor 3 (MTIF3) gene with PD risk. The protein encoded by this nuclear gene is essential for initiation complex formation on the mitochondrial 55S ribosome and regulates translation of proteins within the mitochondria. Changes in the function or expression of the MTIF3 protein may result in altered mitochondrial function, ATP production or formation of reactive oxygen species thereby affecting susceptibility to PD. We examined the association of rs7669 with sporadic PD in three Caucasian case control series (n=2434). A significant association was observed in the largest series (Norwegian; n=1650) when comparing CC vs. CT/TT genotypes, with the Irish and US series having a similar but non-significant trend. The combined series also revealed an association with risk of PD (P=0.01), supporting the possible involvement of this gene in PD etiology.     

Association of GWAS loci with PD in China

Genome‐wide association studies (GWAS) have identified numerous single‐nucleotide polymorphisms (SNPs) at four loci (SNCA, PARK16, LRRK2, BST1) that can modulate the risk of Parkinson's disease (PD). The strength of these associations has yet to be clarified in Mainland China. Ethnic specific effect is an important consideration in GWAS analysis. Using a case–control methodology, we genotyped multiple SNPs at these four loci to investigate their association with risk of PD in Mainland China. A total of 1,146 study subjects comprising 636 patients with PD and 510 unrelated healthy controls were recruited. The minor alleles at SNPs rs894278, rs1994090, rs2046932, rs4698412, and rs7304279 were found to be significantly higher in cases than in controls, while the minor alleles were found to significantly reduce the risk of developing PD at SNPs rs823128, rs823156, rs6532194, rs1191532, and rs16856139. These associations remained after taking into considerations the effects of age and gender. We showed that multiple SNPs at LRRK2 and SNCA increase risk of PD, while PARK16 SNPs are associated with a lower risk of PD in China. Our study findings will contribute to further research using GWAS‐linked data and research on ethnic specific effect of common variants. © 2011 Wiley‐Liss, Inc.     

Role of tau kinases (CDK5R1 and GSK3B) in Parkinson's disease: a study from India

Glycogen synthase kinase-3β (GSK3B) and cyclin-dependent kinase 5 (CDK5) are the 2 major protein kinases involved in abnormal phosphorylation of tau. To determine their potential role in the pathogenesis of Parkinson's disease (PD) we analyzed 2 functional single nucleotide polymorphisms (SNPs) of GSK3B (rs334558 and rs6438552) and rs735555 of CDK5 regulatory subunit 1 (CDK5R1) in 373 PD cases and 346 healthy controls of eastern India. The C,C and T,C haplotypes of GSK3B were respectively moderately associated with increased risk and protection for late onset PD (LOPD) (odds ratio [OR], 1.399; 95% confidence interval [CI], 1.069-1.829; p = 0.015, and OR, 0.436; 95% CI, 0.222-0.853; p = 0.016, respectively). Moreover, moderate to significant interaction between different loci were observed for the entire PD cohort or late onset PD only. However, among these interactions, individuals carrying the (C/C) genotype at both loci (rs6438552 and rs735555) had almost twice the risk of developing PD than those without this genotypic combination (OR, 1.871; 95% CI, 1.181-2.964; p = 0.009). Thus, synergistic effect between the 2 major tau kinases, through these SNPs, appears to determine the risk profile for PD.     

Single nucleotide polymorphisms of HER2 related to osteosarcoma susceptibility

Aims: The purpose of this study was to investigate the correlation between single necleotide polymorphisms (SNPs) of human epidermal growth factor receptor-2 (HER2) gene with osteosarcoma susceptibility in Chinese Han population. Methods: 90 patients with osteosarcoma and 100 healthy controls who were frequency-matched with the former by age and gender were enrolled for a case-control study. 5 SNPs of HER2, namely rs2952155, rs1810132, rs2952156, rs1136201 and rs1058808, were tested by Sequenom time of flight mass spectrometry technique. The linkage disequilibrium and haplotype were analyzed using haploview software. The risk intensity of osteosarcoma was expressed by odds ratio (OR) with 95% confidence interval (CI) which was calculated by chi-squared text. Hardy-Weinberg equilibrium (HWE) was also evaluated by chi-squared text. Results: HER2 gene rs1136201 and rs1058808 polymorphisms were associated with the increased risk of osteosarcoma (P=0.04 and 0.02, respectively). Allele G in rs1136201 was 1.67 higher risk for osteosarcoma in cases than the control group (OR=1.67, 95% CI=1.11-2.51) and G allele of rs1058808 polymorphism also significantly increased osteosarcoma susceptibility (OR=2.06, 95% CI=1.27-3.22). The haplotype analysis showed that haplotype C-T-G-G might be a susceptible haplotype to osteosarcoma (OR=1.74, 95% CI=1.01-3.00). HWE test was eligible in controls (P>0.05). Conclusion: HER2 gene rs1136201 and rs1058808 polymorphisms and haplotype C-T-G-G may be related to osteosarcoma susceptibility in Chinese Han population, indicating that the interaction of gene polrmorphism plays an role in osteosarcoma risk.     

Alzheimer's disease and Parkinson's disease genome-wide association study top hits and risk of Parkinson's disease in Korean population

Alzheimer's disease (AD) and Parkinson's disease (PD) have overlapping clinical and pathological features, suggesting a common pathway for these 2 neurodegenerative disorders. Here we investigated the association of both AD and PD GWAS top hits with PD susceptibility. We selected 25 single nucleotide polymorphisms (SNPs) in 9 genes (ABCA7, APOE, BST1, CLU, CR1, LRRK2, PARK16, PICALM, and SNCA) that were genotyped in 1036 PD case patients and 1208 controls. Case patients and controls were all ethnic Koreans. Logistic regression analysis was performed to calculate age- and sex-adjusted odds ratios. None of the AD-susceptibility loci (ABCA7, APOE, CLU, CR1, and PICALM) showed statistically significant association with PD susceptibility. In contrast, we replicated associations of SNCA, LRRK2, BST1, and PARK16 with PD susceptibility in Koreans. Of those, the SNCA SNP rs11931074 showed the most significant association with PD susceptibility (adjusted odds ratio = 1.48; 95% confidence interval = 1.31–1.67; p = 2.20E-10). In a logistic regression analysis with SNPs coded under an additive model, there was no significant genetic interaction between the LRRK2 and the PARK16 locus gene RAB7L1 in PD risk. Our results confirm the associations of SNCA, LRRK2, BST1, and PARK16 with PD susceptibility and fail to show significant associations of AD genome-wide association study (GWAS) top hits with PD susceptibility in a Korean population.     

PITX3 polymorphism is not associated with Parkinson's disease in a Chinese population

Several studies have indicated that three PITX3 single nucleotide polymorphisms (SNPs), rs2281983, rs4919621 and rs3758549, are likely to be associated with Parkinson's disease (PD) in Caucasians. Some studies also suggested an age-of-onset effect. We recently reported that allele and genotype frequencies did not differ between late-onset PD (LOPD) patients and controls for all three SNPs. To extend the analysis to early-onset PD (EOPD) patients, and to test whether an age-of-onset effect exists in Chinese, we genotyped these SNPs in 290 Chinese EOPD patients using a ligase detection reaction (LDR). For all three SNPs, allele and genotype frequencies did not differ between total PD patients and controls, between LOPD patients and controls, between EOPD patients and controls, or between LOPD and EOPD patients. Our results suggest that these PITX3 SNPs do not contribute to the risk of developing PD in EOPD or LOPD in Chinese.     

Analysis of mutations and the association between polymorphisms in the cerebral dopamine neurotrophic factor (CDNF) gene and Parkinson disease

Neurotrophic factors support the survival of dopaminergic neurons. The cerebral dopamine neurotrophic factor (CDNF) is a novel neurotrophic factor with strong trophic activity on dopaminergic neurons comparable to that of glial cell line-derived neurotrophic factor (GDNF). To investigate whether rare or common variants in CDNF are associated with Parkinson disease (PD), we performed mutation analysis of CDNF and a genetic association study between CDNF polymorphisms and PD. We screened 110 early-onset Parkinson disease (EOPD) patients for CDNF mutations. Allelic and genotype frequencies of 3 CDNF single nucleotide polymorphisms (SNPs) (rs1901650, rs7094179, and rs11259365) were compared in 215 PD patients and age- and sex-matched controls. We failed to identify any mutations in CDNF among the EOPD patient sample population. We observed a trend towards increased risk for PD in patients carrying the C allele of SNP rs7094179 (odds ratio (OR)=1.27, 95% confidence interval (CI) 0.96-1.67). Patients carrying the C allele were susceptible to PD in both dominant (CC+CA vs. AA; OR=7.20, 95% CI 0.88-59.1) and recessive (CA+AA vs. CC; OR=0.64, 95% CI 0.41-0.99) models. Genotype and allele frequencies of SNPs rs1901650 and rs11259365 did not differ between PD patients and controls. Our study suggests that the C allele of an intronic CDNF SNP (rs7094179) might be an allele for susceptibility to PD. Further studies with larger sample size are required to confirm our results.     

Association of PTEN gene polymorphisms with liver cancer risk

Objective: To find out if there are any relationship between three single nucleotide polymorphisms (SNPs) of phosphatase and tensin homolog (PTEN) gene (rs1234213, rs1234220, and rs2299939) and the susceptibility of liver cancer. Methods: Genotypes of the three SNPs in the PTEN gene were achieved utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Comparison of genotypes and alleles distribution differences between the case and the control subjects was accomplished with χ² test. The analysis of linkage disequilibrium (LD) and haplotypes of the three SNPs was performed using SHEsis software. We adopted odds ratios (ORs) with 95% confidence intervals (95% CIs) to show the relative risk of liver cancer. Results: TC genotype and C allele of rs1234220 polymorphism showed much more frequently in cases than in controls, reflecting that the TC genotype and the C allele may be linked to the increased risk of liver cancer (OR=2.225, 95% CI=1.178-4.204; OR=1.941, 95% CI=1.124-3.351). Rs2299939 polymorphism showed an opposite result that the GT genotype probably reduce the risk of liver cancer (OR=0.483, 95% CI=0.259-0.900). Statistical significance was not found in the distribution differences of the genotypes of rs1234213 between two groups. LD and haplotype analysis results of the three SNPs showed that the T-C-G haplotype frequency was much higher in cases than in healthy objects, which proved that the T-C-G haplotype might be a susceptibility haplotype for liver cancer (OR=3.750, 95% CI=1.396-10.077). Conclusions: PTEN gene polymorphisms might relate to liver cancer risk.     

Association of the TGF-�� receptor genes with abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a multifactorial condition. The transforming growth factor β (TGF-β) pathway regulates vascular remodeling and mutations in its receptor genes, TGFBR1 and TGFBR2, cause syndromes with thoracic aortic aneurysm (TAA). The TGF-β pathway may be involved in aneurysm development in general. We performed an association study by analyzing all the common genetic variants in TGFBR1 and TGFBR2 using tag single nucleotide polymorphisms (SNPs) in a Dutch AAA case–control population in a two-stage genotyping approach. In stage 1, analyzing 376 cases and 648 controls, three of the four TGFBR1 SNPs and nine of the 28 TGFBR2 SNPs had a P<0.07. Genotyping of these SNPs in an independent cohort of 360 cases and 376 controls in stage 2 confirmed association (P<0.05) for the same allele of one SNP in TGFBR1 and two SNPs in TGFBR2. Joint analysis of the 736 cases and 1024 controls showed statistically significant associations of these SNPs, which sustained after proper correction for multiple testing (TGFBR1 rs1626340 OR 1.32 95% CI 1.11–1.56 P=0.001 and TGFBR2 rs1036095 OR 1.32 95% CI 1.12–1.54 P=0.001 and rs4522809 OR 1.28 95% CI 1.12–1.46 P=0.0004). We conclude that genetic variations in TGFBR1 and TGFBR2 associate with AAA in the Dutch population. This suggests that AAA may develop partly by similar defects as TAA, which in the future may provide novel therapeutic options.     

Screening for replication of genome-wide SNP associations in sporadic ALS

We recently reported a joint analysis of genome-wide association (GWA) data on 958 sporadic amyotrophic lateral sclerosis (ALS) cases and 932 controls from Ireland and the publicly available data sets from the United States and the Netherlands. The strongest pooled association was rs10260404 in the dipeptidyl-peptidase 6 (DPP6) gene. Here, we sought confirmation of joint analysis signals in both an expanded Irish and a Polish ALS cohort. Among 287 522 autosomal single-nucleotide polymorphisms (SNPs), 27 were commonly associated on joint analysis of the Irish, US and Dutch GWAs. These 27 SNPs were genotyped in an expanded Irish cohort (312 patients with SALS; 259 controls) and an additional Polish cohort (218 patients; 356 controls). Eleven SNPs, including rs10260404, reached a final P-value below 0.05 in the Irish cohort. In the Polish cohort, only one SNP, rs6299711, showed nominal association with ALS. Pooling of data for 1267 patients with ALS and 1336 control subjects did not identify any association reaching Bonferroni significance (P<1.74 x 10(-7)). The present strategy did not reveal any consistently associated SNP across four populations. The result for DPP6 is surprising, as it has been replicated elsewhere. We discuss the possible interpretations and implications of these findings for future ALS GWA studies both within and between populations.     

Is KIF24 a genetic risk factor for Frontotemporal Lobar Degeneration?

Linkage analysis identified a region on chromosome 9p associated with Frontotemporal Lobar Degeneration (FTLD). A detailed analysis of candidate genes lying in this region demonstrated an association with Ubiquitin Associated Protein (UBAP)1. The distribution of five Single Nucleotide Polymorphisms (SNPs) located in the chromosome 9 haplotype identified via linkage analysis, including UBAP1 rs7018487, UBAP2 rs1785506 and rs307658, and KIF24 rs17350674 and rs10814083, has been determined in a population of 284 patients diagnosed with FTLD, including 245 with behavioural variant Frontotemporal Dementia (bvFTD), 23 with Progressive Aphasia and 16 with Semantic Dementia, compared with 318 age-matched controls. A statistically significant increased frequency of the KIF24 rs17350674 AA genotype was observed in patients compared with controls (7.4 versus 2.5%; P = 0.0068, OR: 3.63, CI: 1.58–8.35). Considering each syndrome separately, similar results where obtained in bvFTD versus controls (7.7 versus 2.5%, P = 0.005, OR: 3.26, CI: 1.40–7.57). Stratifying for gender, a statistically significant increased genotypic frequency was observed in female patients as compared with female controls (8.9 versus 2.5%, P = 0.008, OR: 3.85, CI: 1.36–10.93). In silico analysis predicted that the substitution from W to L caused by the rs17350674 affects protein function (P < 0.05). The KIF24 rs17350674 polymorphism likely acts as a risk factor for sporadic FTLD, but a replication study would be needed to confirm these preliminary findings.     

Association between AKT1 gene and Parkinson's disease: a protective haplotype

Variation in AKT1 has been associated with schizophrenia, bipolar disease and type II diabetes. The aim of the present study was to investigate the potential role of variability within AKT1 as a risk factor for Parkinson's disease (PD). We performed a case-control association analysis of AKT1 in a Greek cohort of PD using four tagging SNPs and five constructed haplotypes. To assess the structure of this locus in different populations we have performed linkage disequilibrium (LD) analysis using these variants [dunning]. In multilocus analysis, the frequency of a four-SNP1/2/3/4 haplotype was significantly higher in controls in comparison with PD patients (chi(2)=19.76, p=0.00009, OR=0.11 C.I.=0.03-0.35). The association remained significant even after Bonferroni correction for the number of haplotypes (p=0.0002). So, this certain haplotype was significantly associated with reduced risk of the disease. The data presented here suggest the involvement of AKT1 in protection of PD through many possible mechanisms involving different signaling pathways that could be potential therapeutic targets in the future.     

Tankyrase 1 polymorphism associated with an increased risk in developing non-small cell lung cancer in a Chinese population: a proof-of-principle study

Objectives: Tankyrase 1 (TNKS1), a poly (ADP-ribose) polymerase, regulates telomere length and apoptosis in cells, overexpression of which occurred in non-small cell lung cancer (NSCLC). This study investigated TNKS1 single-nucleotide polymorphisms (SNPs) for association with a risk in NSCLC development in a Chinese population. Methods: NSCLC cases and healthy controls of 500 each were recruited for genotyping of 24 TNKS1 SNPs. The association between genotype and NSCLC risk was evaluated by computing the odds ratio (OR) and 95% confidence interval (CI) with multivariate unconditional logistic regression analyses. Haploview software was to analyze association between haplotypes and NSCLC risk. Results: TNKS1 rs6601328 A allele was associated with a lower risk in developing NSCLC and adenocarcinoma (ADC) (OR=0.71; 95% CI, 0.51-0.99 and OR=0.70; 95% CI, 0.50-0.99), whereas TNKS1 rs11991621 C allele (OR=1.44; 95% CI, 1.03-2.03), rs11991621 C/C (OR=1.44, 95% CI, 1.03-2.35; P=0.03), and rs10503380 G/G (OR= 1.56, 95% CI, 1.09-2.50, P=0.02) were associated with a higher risk in developing NSCLC or ADC in females and rs6601328 A/A major allele (OR=1.39; 95% CI, 1.00-1.92; P=0.047) and rs7015700 G/G (OR= 1.51, 95% CI, 1.04-2.21) was associated with an increased NSCLC or ADC risk in males but a reduced NSCLC risk (OR=0.63; 95% CI, 0.42-0.96) and ADC risk (OR=0.64; 95% CI, 0.42-0.97) in females. Haploview showed that there were three Haplotype Blocks associated with NSCLC risk. However, TNKS1 rs12541709 C/C was associated with protective effect against ADC (OR=0.75; 95% CI, 0.56-0.99; P=0.04) in this Chinese population. Conclusion: TNKS1 SNPs (rs11991621 rs10503380, and rs7015700) were associated with NSCLC risk, whereas rs6601328 and rs12541709 inversely associated with NSCLC or ADC risk in this Chinese population.     

Renal cell carcinoma risk is associated with the interactions of APOE,VHL and MTHFR gene polymorphisms

Objective: The study was designed to explore the association of renal cell carcinoma (RCC) with VHL (rs779805), MTHFR (rs1801133) and APOE (rs8106822 and rs405509) polymorphisms, investigate the interactions among the single nucleotide polymorphisms (SNPs), and explore roles of the interactions in the pathogenesis of RCC in Chinese Han population. Methods: 81 RCC patients and 80 healthy controls were included in the study. Polymerase chain reaction (PCR) and direct sequencing methods were used in the analysis on the genotypes of APOE, VHL and MTHFR gene polymorphisms. Multifactor dimensionality reduction (MDR) method was adopted to conduct gene-gene interaction analysis. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were utilized to evaluate the correlation between gene-gene interactions and RCC risk. Results: Significant correlations were found between RCC risk and 3 SNPs (rs8106822, rs779805 and rs1801133). Genotype AA and allele A of APOE rs8106822 were significantly associated with RCC susceptibility (OR=2.65, 95% CI=1.05-6.69). Meanwhile, we found that the frequencies of genotype GG and allele G were much higher in case group, compared with controls (P<0.05 for both) and they appeared to be risk factors for RCC (OR=2.90, 95% CI=1.22-6.87; OR=1.78, 95% CI=1.14-2.27). While, allele T of MTHFR rs1801133 could decrease the risk of RCC (OR=0.62, 95% CI=0.40-0.97). MDR analysis showed that gene-gene interactions among APOE, VHL and MTHFR SNPs were closely related with RCC susceptibility. Conclusion: APOE, VHL and MTHFR gene polymorphisms were related to the risk of RCC. The interactions among APOE, VHL and MTHFR genes could increase the risk of RCC.