Association of polymorphisms in the interleukin-4 gene with response to hepatitis B vaccine and susceptibility to hepatitis B virus infection: A meta-analysis

Objective

The aim of this meta-analysis is to evaluate the associations between functional polymorphisms in the interleukin-4 (IL4) gene and individuals' responses to hepatitis B vaccine and their susceptibility to hepatitis B virus (HBV) infection.

Methods

A literature search on articles published before December 1st, 2012 was conducted in PubMed, Embase, Web of Science and China BioMedicine (CBM) databases. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Statistical analyses were performed using the STATA 12.0 software.

Results

Eight studies were eligible for inclusion in this meta-analysis, including five cross-sectional studies on individual's response to hepatitis B vaccine and three case–control studies on HBV infection risk. The meta-analysis results showed that the T allele of rs2243250, the T allele of rs2070874, and the C allele of rs2227284 in IL4 gene were associated with high responses to hepatitis B vaccine. Further subgroup analysis by ethnicity showed that there was a significant association between IL4 genetic polymorphisms and an individual's responses to hepatitis B vaccine among Asian populations, but similar association was not found among Caucasian populations. However, there was no evidence indicating a correlation between IL4 genetic polymorphism and susceptibility to HBV infection.

Conclusion

Our current meta-analysis suggests that rs2243250, rs2070874 and rs2227284 polymorphisms in IL4 gene may play an important role in determining the response to hepatitis B vaccine, especially among Asian populations. However, further studies are still needed to evaluate the associations between IL4 genetic polymorphisms and HBV infection risk.     

Association study of TLR-9 polymorphisms and systemic lupus erythematosus in Northern Chinese Han population

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease, with multiple genetic and environmental factors involving in its etiology. The toll-like receptor 9 (TLR9) gene has been reported to have important roles in the development and progression of SLE. We performed a case–control study to investigate the effects of 4 SNPs in the TLR9 gene in the development of SLE in Northern Chinese population.

Methods

Four SNPs including rs187084, rs5743836, rs352139 and rs352140 were genotyped using the SNaPshot® method. A group of 430 SLE patients were compared to 424 normal controls. Data were analyzed by SPSS 17.0 and HaploView v 4.1 software.

Results

The frequency distributions of SNP rs351240 and haplotype H2 (TGCT) and H3 (CATT) were found to differ significantly between patient and control groups (p < 0.05), while other SNPs and haplotypes showed no significant difference between the two cohorts (p > 0.05).

Conclusion

The results revealed that variations in the TLR9 gene are associated with SLE, indicating that TLR9 may play an important role in the pathogenesis of SLE in the northern Chinese Han population.     

Association Analysis between SNPs in IL-28B Gene and the Progress of Hepatitis B Infection in Han Chinese

Objective

As a candidate gene association study, we investigated the genetic association of SNPs in IL-28B genes with different outcomes of HBV infection, including LC and HCC occurrence.

Methods

Chinese Han subjects were categorized into two groups: 406 LC caused by CHB and 406 HCC caused by CHB. Genomic DNA was isolated from whole blood samples, SNPs were detected using high resolution melting curve (HRM) method. PCR amplification was carried out under the same conditions in a 96-well plate in Real-Time PCR System. Then 341 LC and 356 HCC patients caused by HBV infection were analyzed as a verification by independent sample. 393 CHB patients and 244 health subjects were included as control.

Results

CHB patients who progress to LC or HCC showed a significant different frequency in rs12979860 (p = 0.046). Patients with HCC carried more frequently the T alleles in rs12979860 comparison to LC. Same results were found in the independent sample.

Conclusion

IL-28B rs12979860 C/T polymorphism T allele appears to be more prevalent in patients with HCC than in LC. Carriage of this allele seems to enhance the risk for developing HCC. Gene polymorphism of IL-28B may confer symptomatic specificity in progress and extent of hepatitis B infection.     

Association study of CRP gene polymorphism and hypertension in Han Chinese population

Background

Serum C-reactive protein (CRP) and genetic variation of CRP gene have been reported as a strong, independent predictor of myocardial infarction and stroke. But there is rare association evidence of CRP genetic variation and hypertension (HT).

Methods

A community-based case–control study including 1331 cases with HT and 1400 controls was used to evaluate the association of tagSNPs covered CRP gene, CRPP1 gene and 40 kb upstream with HT in a Chinese Han population. Haplotypes and stratification analysis were applied to further evaluate relationships between the screened SNPs and HT and general linear model (GLM) was applied to compare blood pressure levels between genotypes.

Results

In stage 1, five SNPs had positive association with HT (P < 0.05) and entered stage 2 and two SNPs rs876537 and rs10737175 polymorphisms showed significant association with HT in joint sample. Haplotype analysis showed that comparing with common haplotype T–C which was constructed by rs6677719 and rs10737175, haplotype T–T significantly associated with HT after adjusted covariates. Stratification analysis found significant associations of HT for rs876537, rs2808630, rs6677719 and rs10737175 in ≥ 50 years group, rs876537, rs10737175 in female, rs876537 and rs10737175 in non-smoking and non-drinking populations as well as rs2808630 in non-drinking population. Furthermore, quantitative trait analysis indicated significant differences of SBP and DBP between the genotypes of rs10737175, rs876537 and rs2808630 in non-treatment hypertensive cases and control population.

Conclusions

The findings of this study support that CRP gene polymorphisms have significant association with genetic susceptibility of HT and quantitative traits of blood pressure.     

Polymorphisms of the TLR4 gene and risk of gastric cancer

Objective

Toll-like receptor 4 (TLR4) is an important lipo-polysaccharide (LPS) receptor in gastric epithelial cell signaling transduction and plays critical roles in the development and progression of gastric cancer (GC). We investigated the effects of TLR4 gene polymorphisms and gene–environmental interactions on the risk of GC in Northeastern China.

Methods

We genotyped two single-nucleotide polymorphisms (SNPs) in TLR4 (rs10116253 and rs1927911) in 217 GC patients and 294 cancer-free controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Odds ratio (OR) and 95% confidence intervals (CIs) were estimated by unconditional logistic-regression models.

Results

Individuals carrying CC genotype of rs10116253 and TT genotype of rs1927911 had a significantly decreased risk of GC (adjusted OR = 0.33, 95% CI 0.18–0.60, P < 0.001 and adjusted OR = 0.37, 95% CI 0.21–0.67, P = 0.001 respectively), compared with TT genotype of rs10116253 and CC genotype of rs1927911. In addition, the SNP effects were additive to the effects of some known environmental factors without any interaction between them in the susceptibility to GC.

Conclusion

Our data suggested that TLR4 gene polymorphisms may be associated with a decreased risk of GC in Chinese population. And these SNPs and their combined effects with environmental factors may be associated with the risk of GC.     

Impacts of TCF7L2 gene polymorphisms on the susceptibility of hepatogenous diabetes and hepatocellular carcinoma in cirrhotic patients

Background

Hepatogenous diabetes (HD) occurs as a complication of cirrhosis. Whether genetic factors, rather than only liver damage, play roles in the development of HD is unknown. TCF7L2 gene has been reported to be associated with type 2 diabetes and also cancer risks. We aim to evaluate the impact of TCF7L2 gene on the susceptibility of HD and hepatocellular carcinoma (HCC) in a Chinese Han population.

Patients and methods

A total of 367 adult liver transplant candidates with liver cirrhosis were included. Fifteen tag single nucleotide polymorphisms (SNPs) were selected from HapMap CHB database with a minor allele frequency of > 0.2 and r² of > 0.8. Another three SNPs were also chosen because of their close association with type 2 diabetes in East Asian.

Results

Patients with HD presented significantly poorer liver function, higher incidence of cirrhotic complications and higher insulin resistance compared with non-HD patients. Three SNPs were differentially distributed between HD patients and non-HD patients. In multivariate logistic analysis, TCF7L2 rs290487 and rs6585194 polymorphisms were independently associated with HD after adjustment of clinical factors. The TCF7L2 rs290487 C/C variant homozygote showed much higher insulin resistance and significantly increased HD risk comparing with T/T and T/C genotypes, while the genetic variant of rs6585194 was protectively against HD. Three SNPs (rs290481, rs290487 and rs290489) located near the 3′ end of TCF7L2 gene were associated with HCC risk with marginal significance. Patients carrying G-C-A haplotype had a significantly higher HCC risk than those with A-T-G.

Conclusions

TCF7L2 polymorphisms were associated with HD and maybe cancer risk as well. Further studies with large samples are needed to verify these results.     

DCC (deleted in colorectal carcinoma) gene variants confer increased susceptibility to gallbladder cancer (Ref. No.: Gene-D-12-01446)

Background and aim

GBC is a lethal and multifaceted disease. Deleted in colorectal carcinoma (DCC) is a well known tumor suppressor gene. Recently a small genome-wide association study (GWAS) identified DCC to be significantly associated with gallbladder cancer (GBC) susceptibility in a Japanese population sample. However, the study sample size was small and lacked independent replication. Therefore, the present study was carried out to replicate the association of two GWAS identified DCC SNPs (A>G_rs4078288, C>T_rs7504990) and two other SNPs (C>G_rs2229080 and A>G_rs714) previously associated with various cancers.

Methodology

The study was accomplished in 406 GBC cases and 260 healthy control samples from North India. Genotyping was carried out by PCR-RFLP and Taqman genotyping assays. Statistical analysis was performed by using SPSS ver16 and functional prediction of these variants was carried out using Bioinformatics tools (FAST-SNP, F-SNP).

Result

We did not observe association with GWAS-identified SNPs of DCC but other SNPs showed significant association. In addition, a DCC haplotype G_rs2229080-A_rs4078288-C_rs7504990-A_rs714 conferred high risk of GBC in India. The haplotype associated risk was independent of gallstone, sex or tobacco usages which are well-known modifiers of GBC risk. Further analysis suggested DCC A>G_rs714 as a major risk conferring SNP in the Indian population.

Conclusion

This study re-affirms the role of plausible tumor suppressor DCC variants, in gallbladder carcinogenesis and the risk haplotype may be explored as a useful marker for GBC susceptibility.     

Genetic variants in selenoprotein P plasma 1 gene (SEPP1) are associated with fasting insulin and first phase insulin response in Hispanics

Context

Insulin resistance is not fully explained on a molecular level, though several genes and proteins have been tied to this defect. Knockdowns of the SEPP1 gene, which encodes the selenoprotein P (SeP) protein, have been shown to increase insulin sensitivity in mice. SeP is a liver-derived plasma protein and a major supplier of selenium, which is a proposed insulin mimetic and antidiabetic agent.

Objective

SEPP1 single nucleotide polymorphisms (SNPs) were selected for analysis with glucometabolic measures.

Participants and measures

The study included1424 Hispanics from families in the Insulin Resistance Atherosclerosis Family Study (IRASFS). Additionally, the multi-ethnic Insulin Resistance Atherosclerosis Study was used. A frequently sampled intravenous glucose tolerance test was used to obtain precise measures of acute insulin response (AIR) and the insulin sensitivity index (S_I).

Design

21 SEPP1 SNPs (tagging SNPs (n = 12) from HapMap, 4 coding variants and 6 SNPs in the promoter region) were genotyped and analyzed for association.

Results

Two highly correlated (r² = 1) SNPs showed association with AIR (rs28919926; Cys368Arg; p = 0.0028 and rs146125471; Ile293Met; p = 0.0026) while rs16872779 (intronic) was associated with fasting insulin levels (p = 0.0097). In the smaller IRAS Hispanic cohort, few of the associations seen in the IRASFS were replicated, but meta-analysis of IRASFS and all 3 IRAS cohorts (N = 2446) supported association of rs28919926 and rs146125471 with AIR (p = 0.013 and 0.0047, respectively) as well as rs7579 with S_I (p = 0.047).

Conclusions

Overall, these results in a human sample are consistent with the literature suggesting a role for SEPP1 in insulin resistance.     

NOD2 gene mutations associate weakly with ulcerative colitis but not with Crohn's disease in Indian patients with inflammatory bowel disease

Background

Three mutations (two missense and one frameshift) in the NOD2 gene are associated with Crohn's disease (CD) in a proportion of patients with Crohn's disease in North America, Europe and Australia. These three mutations are not found in Indian patients with CD. We undertook new studies to identify polymorphisms in the NOD2 gene in the Indian population and to detect whether any of these were associated with inflammatory bowel disease (IBD) in this population.

Methods

Individual exons of the NOD2 gene were amplified by PCR and subjected to denaturing high performance liquid chromatography (DHPLC) to detect heteroduplex formation. All 12 exons of the NOD2 gene were amplified and Sanger-sequenced to detect polymorphisms in the NOD2 gene. 310 patients with CD, 318 patients with ulcerative colitis (UC) and 442 healthy controls (HC) were recruited for association studies. DNA from these participants was evaluated for the identified eight polymorphisms by Sequenom analysis.

Results

Heteroduplex formation was noted by DHPLC in exons 2 and 4 of the NOD2 gene. Sequencing of the entire NOD2 gene data revealed eight polymorphisms – rs2067085, rs2066842, rs2066843, rs1861759, rs2111235, rs5743266, rs2076753, and rs5743291 – of which the latter four were described for the first time in Indians. None of these polymorphisms was associated with CD. The SNPs rs2066842 and rs2066843 were in significant linkage disequilibrium. Both SNPs showed a significant association with UC (P = 0.03 and 0.04 respectively; odds ratio 1.44 and 1.41 respectively).

Conclusion

Four NOD2 polymorphisms were identified for the first time in the Indian population. Of 8 NOD2 polymorphisms, none were associated with CD but two were weakly associated with UC. NOD2 polymorphisms do not play a major role in CD genesis in India.     

Genetic polymorphisms of IFNG and IFNGR1 in association with the risk of pulmonary tuberculosis

Objective

Genetic host factors play an important role in controlling individual's susceptibility to the pathogen. This study aims to explore the single and joint effect of genetic polymorphisms of interferon-gamma (IFNG) and its receptor (IFNGR1) in association with the pulmonary tuberculosis in a Chinese Han population.

Methods

This population-based case control study consisted of 1434 pulmonary tuberculosis patients and 1412 healthy controls. Six tag SNPs in IFNG/IFNGR1 were genotyped using TaqMan allelic discrimination technology. The logistic regression model was carried out to analyze the associations between the genotypes and haplotypes and the risk of tuberculosis by calculating the odds ratio (OR) and 95% confidence interval (CI).

Results

After the Bonferroni correction for multiple comparisons, three SNPs (rs2234711, rs1327475 and rs7749390) in IFNGR1 gene were observed to be significantly associated with the altered risks of tuberculosis. For the SNP rs2234711, individuals carrying C allele (vs. T) showed a decreased risk, with the adjusted OR(95% CI) of 0.82(0.76–0.91). The additive model revealed that each additional allele contributed about 14% decreased risk (OR: 0.86, 95% CI: 0.77–0.95). Moreover, we observed a strong linkage disequilibrium between rs2234711 and rs3799488. Compared with the common rs2234711C–rs3799488C haplotype, the haplotype rs2234711T–rs3799488C contributed to a significant increase in the risk of tuberculosis (adjusted OR: 1.24, 95% CI: 1.09–1.41).

Conclusions

Our results suggest that genetic polymorphisms in IFNGR1 gene are involved in the risk of tuberculosis in the Chinese population. Future studies should include a comprehensive sequencing analysis to identify the specific causative sequence variants underlying the observed associations.     

Functional polymorphisms in the interleukin-12 gene contribute to cancer risk: Evidence from a meta-analysis of 18 case–control studies

Background

Emerging evidence from preclinical and clinical studies has shown that interleukin-12 (IL-12) has some effectiveness against endogenously arising carcinogenesis. Several potentially functional polymorphisms of IL-12 gene have been implicated in cancer risk, but individually published studies showed inconclusive results. The aim of this study was to investigate the association between IL-12 polymorphisms and cancer risk.

Methods

The MEDLINE, EMBASE, Web of science and CBM databases were searched for all articles published up to June 10, 2012 that addressed IL-12 polymorphisms and cancer risk. Statistical analyses were performed using RevMan 5.1.6 and STATA 12.0 softwares.

Results

Eighteen studies were included with a total of 6463 cancer cases and 7412 healthy controls. We found that the 3'UTR A > C (rs3212227) polymorphism of IL-12B gene was associated with significantly increased overall risk of cancers using random effects model (C vs A: odds ratio [OR] = 1.14, 95% confidence interval [CI]: 1.02-1.27; AC + CC vs AA: OR = 1.20, 95%CI: 1.01-1.43). However, the 3'UTR G > A (rs568408), IVS2 T > A (rs582054) and 5'UTR T > G (rs2243115) polymorphisms of IL-12A gene did not appear to have an influence on cancer susceptibility. Further subgroup analyses showed that the 3'UTR A > C (rs3212227) polymorphism was associated with increased cancer risks in the subgroups of Asians, cervical and nasopharyngeal cancers.

Conclusions

Results from the current meta-analysis indicates that the 3'UTR A > C (rs3212227) polymorphism of IL-12B gene might be a potential biomarker for cancer risk among Asians, especially for cervical and nasopharyngeal cancers.     

Genetic variants associated with the progression of hepatocellular carcinoma in hepatitis C Egyptian patients

Background

Hepatocellular carcinoma (HCC) associated to infection with hepatitis C virus (HCV) has become the fastest-rising cause of cancer-related deaths. Genetic variations may play an important role in the development of HCC in HCV patients. Ghrelin exerts anti-inflammatory, antifibrotic and hepatoprotective effects on chronically injured hepatic tissues. Ghrelin gene shows several single nucleotide polymorphisms (SNPs) including − 604G/A, Arg51Gln, and Leu72Met. Hemochromatosis gene (HFE) mutations namely C282Y and H63D may cause hepatic iron overload, thus increasing the risk of HCC in HCV patients.

Aim

To investigate the association of progression of HCC with ghrelin and HFE gene polymorphisms in HCV Egyptian patients.

Methods

Seventy-nine chronic HCV patients (thirty-nine developed HCC and forty did not), and forty healthy control subjects were included in the study. The polymorphisms were evaluated by PCR/RFLP analysis, and related protein levels were measured by either ELISA or colorimetric assays.

Results

The three tested SNPs on ghrelin gene were detected in the studied groups, only one SNP (Arg51Gln) showed significantly higher GA, AA genotypes and A allele frequencies in hepatitis C patients who developed HCC than in hepatitis C patients without HCC and controls. Of the two mutations studied on HFE gene only H63D heterozygous allele was detected, and its frequency did not statistically differ among studied groups.

Conclusion

Our results suggest that A allele at position 346 of the ghrelin gene is associated with susceptibility to HCC in hepatitis C patients.     

Haplotype study of the CYP4A11 gene and coronary artery disease in Han and Uygur populations in China

Background

CYP4A11 converts arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), which has a crucial role in the modulation of cardiovascular homeostasis. We assessed the association between the human CYP4A11 gene and coronary artery disease (CAD) in Han and Uygur populations in China.

Methods and Results

In the Han population, 361 CAD patients and 315 controls were genotyped for four single-nucleotide polymorphisms (SNPs) of the human CYP4A11 gene (rs9332978, rs4660980, rs3890011, rs1126742). In the Uygur population, 331 CAD patients and 182 controls were genotyped for the same four SNPs. Data were assessed via haplotype-based case–control studies. For the Han population, the significance of the recessive model of SNP3 (GG vs. CC+GC) between CAD patients and control subjects was retained after adjustment for EH, DM and smoking (for men, 95% CI: 1.173–3.013, P = 0.009). The G-G-T haplotype in CAD was significantly higher than that in the control group (P = 0.037). In the Uygur population, neither the distribution of genotypes and alleles for the four SNPs nor the distribution of haplotypes constructed with the same three SNPs showed a significant difference between CAD and control subjects.

Conclusions

The GG genotype of rs3890011 and the G-G-T haplotype in the CYP4A11 gene could be a useful genetic marker of CAD in Han populations in China.     

PSCA gene variants (rs2294008 and rs2978974) confer increased susceptibility of gallbladder carcinoma in females

Background and aim

PSCA is a tissue specific tumor suppressor or oncogene which has been found to be associated with several human tumors including gallbladder cancer. It is considered to be involved in the cell-proliferation inhibition and/or cell-death induction activity. Therefore, we aimed to investigate the role of PSCA gene polymorphisms in gallbladder cancer risk in North Indian population.

Methodology

A total of 405 gallbladder cancer patients and 247 healthy controls were included in the case–control study for risk prediction. We examined the association of two functional SNPs, rs2294008 and rs2978974 in PSCA gene by genotyping using Taqman allelic discrimination assays. Statistical analysis was done using SPSS software, version 17. Linkage disequilibrium and haplotype analysis was done with the help of SNPstats software. FDR test was used to correct for multiple comparisons.

Results

No significant associations of rs2294008 and rs2978974 genetic variants of the PSCA gene were found with GBC risk at allele, genotype or haplotype levels. Stratifying the subjects on the basis of gallstone also did not show any significant result. However, on gender stratification, we found a significant association of T_rs2294008-G_rs2978974 haplotype with higher risk of GBC in females (FDR Pcorr = 0.021, OR = 1.6). In contrary, T_rs2294008-A _rs2978974 haplotype conferred significant lower risk in males (FDR Pcorr = 0.013; OR = 0.25).

Conclusions

These findings suggest that PSCA genetic variants may have a significant effect on GBC susceptibility in a gender specific manner.     

Genetic association between IL-17F gene polymorphisms and the pathogenesis of Graves' Disease in the Han Chinese population

Background

Graves' Disease (GD) is a common and complex disorder, with a strong hereditary component. IL-17F is a potent cytokine and a potential contributor to the etiology of various human autoimmune diseases. In the present study, we focused on the relationship between polymorphisms in the IL-17F gene and GD susceptibility through a case–control association study in two independent Chinese cohorts.

Methods

Our pilot study was performed on a cohort from Shanghai, which included 757 GD patients and 741 healthy controls. Our replication cohort was from Xiamen, consisting of 434 GD patients and 420 healthy controls. We selected four tag SNPs (rs763780, rs2397084, rs9463772 and rs761167) within the IL-17F gene to conduct a genotyping analysis.

Results

In the Shanghai cohort, the rs9463772 polymorphism showed a significant association with GD and Graves' Disease-associated Ophthalmopathy (GO) patients (P_allele = 7 × 10^− 5 and 7.4 × 10^− 3 for GD and GO patients, respectively). The rs763780 polymorphism was found to have only a difference in genotype distribution between GD individuals and healthy controls (P = 0.017). In the replication study, we confirmed the association between the rs9463772 polymorphism and GD susceptibility. Haplotype analysis showed that the haplotype of the four SNPs (GCTT) was associated with a significant risk of GD in the Shanghai cohort (P = 7.9 × 10^− 3).

Conclusion

Our results suggest that polymorphisms in the IL-17F gene increase the risk of Graves' Disease and that IL-17F is therefore a good candidate gene for Graves' Disease prediction in the Han Chinese population.     

Receptor for advanced glycation end-product (RAGE) gene polymorphism 2245G/A is associated with pro-inflammatory,oxidative-glycation markers and sRAGE in diabetic retinopathy

Background

Receptor for advanced glycation end-product (RAGE) gene polymorphism 2245G/A is associated with diabetic retinopathy (DR). However, the mechanism on how it affects the disease development is still unclear.

Aim

This study aims to investigate the relationship between 2245G/A RAGE gene polymorphism and selected pro-inflammatory, oxidative-glycation markers in DR patients.

Methods

A total of 371 unrelated type 2 diabetic patients [200 with retinopathy, 171 without retinopathy (DNR)] and 235 healthy subjects were recruited. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism method followed by DNA sequencing. The nuclear and cytosolic extracts from peripheral blood mononuclear cells were used for nuclear factor kappa B (NF-κB) p65 and superoxide dismutase activity measurement respectively. Plasma was used for glutathione peroxidase activity, advanced oxidation protein product (AOPP), monocyte chemoattractant protein (MCP)-1, pentosidine and soluble RAGE (sRAGE) measurements.

Results

DR patients with 2245GA genotype had significantly elevated levels of activated NF-κB p65, plasma MCP-1, AOPP and pentosidine but lower level of sRAGE when compared to DR patients with wild-type 2245GG.

Conclusion

The RAGE gene polymorphism 2245G/A is associated with pro-inflammatory, oxidative-glycation markers and circulating sRAGE in DR patients. Patients with 2245GA RAGE genotype could aggravate DR possibly via NF-κB mediated inflammatory pathway.     

A novel locus for body mass index on 5p15.2: a meta-analysis of two genome-wide association studies

Objective

Genetic factors play an important role in modulating the vulnerability to body mass index (BMI). The purpose of this study is to identify novel genetic variants for BMI using genome-wide association (GWA) meta-analysis.

Methods

PLINK software was used to perform meta-analysis of two GWA studies (the FUSION and Marshfield samples) of 5218 Caucasian individuals with BMI. A replication study was conducted using the SAGE sample with 762 individuals.

Results

Through meta-analysis we identified 33 SNPs associated with BMI with p < 10^− 4. The most significant association was observed with rs2967951 (p = 1.19 × 10^− 6) at 5p15.2 within ROPN1L gene. Two additional SNPs within ROPN1L and 5 SNPs within MARCH6 (the top SNP was rs2607292 with 4.27 × 10^− 6) further supported the association with BMI on 5p15.2 (p < 1.8 × 10^− 5). Conditional analysis on 5p15.2 could not distinguish the effects of ROPN1L and MARCH6. Several SNPs within MARCH6 and ROPN1L were replicated in the SAGE sample (p < 0.05).

Conclusion

We identified a novel locus for BMI. These findings offer the potential for new insights into the pathogenesis of BMI and obesity and will serve as a resource for replication in other populations to elucidate the potential role of these genetic variants in BMI and obesity.     

Genetic Association of Human Leukocyte Antigens with Chronicity or Resolution of Hepatitis B Infection in Thai Population

Background

Previous studies showed that single nucleotide polymorphisms (SNPs) in the HLA-DP, TCF19 and EHMT2 genes may affect the chronic hepatitis B (CHB). To predict the degree of risk for chronicity of HBV, this study determined associations with these SNPs.

Methods

The participants for this study were defined into 4 groups; HCC (n = 230), CHB (n = 219), resolved HBV infection (n = 113) and HBV uninfected subjects (n = 123). The HLA-DP SNPs (rs3077, rs9277378 and rs3128917), TCF19 SNP (rs1419881) and EHMT2 SNP (rs652888) were genotyped.

Results

Due to similar distribution of genotype frequencies in HCC and CHB, we combined these two groups (HBV carriers). The genotype distribution in HBV carriers relative to those who resolved HBV showed that rs3077 and rs9277378 were significantly associated with protective effects against CHB in minor dominant model (OR = 0.45, p<0.001 and OR = 0.47, p<0.001). The other SNPs rs3128917, rs1419881 and rs652888 were not associated with HBV carriers.

Conclusions

Genetic variations of rs3077 and rs9277378, but not rs3128917, rs1419881 and rs652888, were significantly associated with HBV carriers relative to resolved HBV in Thai population.