To perform a meta-analysis of single nucleotide polymorphism needs to calculate gene frequency. This paper employs allele model as an example to introduce how to calculate gene frequency and display the process of a meta-analysis of single nucleotide polymorphism data using Review Manager 5.3 software.
ObjectiveTo analyze the causal relationship between SARS-CoV-2 infection and retinal vascular obstruction by mendelian randomization (MR). MethodsA two-sample MR analysis utilizing summary statistics from genome-wide association studies (GWAS) in European populations was conducted. The GWAS data for SARS-CoV-2 infection comprised cases of common infection (2 597 856), hospitalized infection (2 095 324), and severe infection (1 086 211). Data on retinal vascular obstruction were obtained from the FinnGen database, which included 203 269 cases of retinal artery obstruction and 182 945 cases of retinal vein obstruction (RVO). Inverse variance weighting (IVW), random effects models, weighted median (WM), MR-Egger regression, simple models, and weighted models were used to analyze the bidirectional causal relationship between different SARS-CoV-2 infection phenotypes and retinal obstruction. The Q statistic was used to assess heterogeneity among single nucleotide polymorphisms (SNP), while MR-Presso was utilized to detect SNP outliers, and MR-Egger intercept tests were performed to evaluate horizontal pleiotropy. ResultsThe MR analysis, using IVW, random effects models, MR-Egger, WM, and weighted models, indicated no significant association between common SARS-CoV-2 infection, hospitalized infection, severe infection, and retinal vascular obstruction (P＞0.05). Additionally, retinal vascular obstruction did not show a significant association with the various SARS-CoV-2 infection phenotypes (P＞0.05). In the simple model, a significant association was found between severe SARS-CoV-2 infection and RVO (P＜0.05), as well as between RVO and common SARS-CoV-2 infection (P＜0.05). No heterogeneity was observed in the IVW and MR-Egger analyses (P＞0.05). The MR-Egger test provided no evidence of horizontal pleiotropy (P＞0.05), and MR-Presso detected no outlier SNP. ConclusionThe findings of this study do not support a causal relationship between SARS-CoV-2 infection and the occurrence of retinal vascular obstruction.
Objective To explore the correlation between the single nucleotide polymorphism (SNP) in the promotor of hepatic l ipase (HL) gene and untraumatic avascular necrosis of the femoral head (ANFH). Methods Between January 2007 and June 2009, 243 patients with ANFH were treated (case group), including 143 cases of steroid-induced, 79 cases of alchol-induced, and 21 cases of idiopathic. There were 156 males and 87 females with an age ranged from 16 to 64 years. Atotal of 96 normal individuals (matched for age, sex, and nation) served as control group. The blood sample of all subjects were collected to extract DNA. The promotor of HL was sequenced to find the SNP. A statistic on the frequencies of the genotype and the allele of the SNP was made. The frequencies of the genotype and the allele were analyzed with χ2 test according to case-control principle. Results The rs59644784 and rs1800588 were found in the sequenced region. It was accorded with Hardy-Weinbery genetic equil ibrium law in rs59644784 and rs1800588 of the control group and case group. There was no significant difference in the allele and genotype of rs59644784 and rs1800588 between the control group and case group (P gt; 0.05). The two SNPs existed complete l inkage disequil ibrium according to the l inkage disequil ibrium analysis. Conclusion The heterozygosity of the SNP is not consistency, and heterozygosity may be associated with the diversity of the race. ANFH is not associated with rs59644784 and rs1800588 SNPs.
ObjectiveTo explore the single locus mutation that related to hepatitis B virus (HBV) co-infection by means of genome-wide association study (GWAS) in Chinese Han patients with pulmonary tuberculosis (TB).MethodsA total of 946 patients with pulmonary TB enrolled between March 2013 and March 2018 were genotyped by Illumina Human Omni Express gene chip. After quality control, 389 972 single nucleotide polymorphisms (SNPs) of 703 patients with single TB infection and 53 patients with TB-HBV co-infection were included in the follow-up association analysis.ResultsThe SNP with the strongest statistical correlation signal was rs118122819 (P=2.923×10?12, odds ratio=7.933) located on chromosome 8p23.1. Other potential susceptibility genes included CDH4 (rs73309833), MARCH1 (rs3797020), and DNER (rs13393112), etc. In addition, a strong linkage imbalance between rs118122819 and rs4840365 (D’=0.88, r2=0.76) was found, while rs4840365 was located in the MFHAS1 gene region.ConclusionsThis study provides evidence for the presence of susceptibility gene locus for HBV co-infection in pulmonary TB patients, and provides important clues for the mechanism research, disease prevention, and treatment of co-infection. But these associations must be replicated and validated in larger studies.
Objective To review the research progress in relationship between hereditary diffuse gastric cancer (HDGC) and CDH1 gene. Methods Literatures on HDGC which were published in recent years were collected and analyzed. Results Aberrant CDH1 gene is significantly correlated with HDGC: mutations of CDH1 exons play the most important role in pathogenesis of HDGC. Screening CDH1 gene mutation is useful for diagnosis of HDGC as well as the treatments. Alterations of CDH1 other than exon mutation, such as intron mutation, gene promoter methylation and single nucleotide polymorphism may result in downregulation of the gene expression. Further study should be done to confirm the roles of these alterations. Conclusions Alterations of CDH1 gene are significantly associated with the pathogenesis of HDGC. Detecting alterations of CDH1 gene are important for diagnosis and management of HDGC as well as to get insights of the pathogenesis of the disease.
Objective
To explore the relationships between the polymorphisms of inhibitor genes WIF1 and DKK1 in WNT signaling pathway and susceptibility to tuberculosis, clinical characteristics and laboratory indexes.
Methods
From December 2014 to November 2016, 475 tuberculosis patients and 370 healthy controls of West China Hospital of Sichuan University were enrolled in the study, and the clinical data of the subjects were collected. High-throughput genotyping technique was used to detect the polymorphisms of WIF1 rs58635985 and DKK1 rs11001548 in WNT signaling pathway. The allele frequency distribution, genotype, genetic model, clinical features and laboratory indexes of two single nucleotide polymorphisms were analyzed by χ2 test and logistic regression analysis.
Results
There was no significant difference in the allele frequency distribution (P=0.275, 0.949), genotype (P=0.214, 0.659) or genetic models: additive model (P=0.214, 0.659), dominant model (P=0.414, 0.827), recessive model (P=0.227, 0.658) of rs58635985 and rs11001548 between the tuberculosis group and the healthy control group. Subgroup analysis showed no significant difference in allele and genotype distribution between rs58635985 and rs11001548 (pulmonary tuberculosis group vs. healthy control group: P>0.05; pulmonary tuberculosis groupvs. extra-pulmonary tuberculosis group: P>0.05). There was no significant difference in the clinical features (fever, night sweat, fatigue,etc.) or laboratory indexes (complete blood count, erythrocyte sedimentation rate, TB-DNA, etc.) (P>0.05).
Conclusions
There is no association between rs58635985 of WIF1 gene or rs11001548 of DKK1 gene and genetic susceptibility, clinical characteristics and laboratory indexes in Han population in Western China. To expand the sample size for verification and analysis in different populations is necessary.
Objective To investigate whether ADAM33 ( A disintegrin and metalloproteinase 33) gene polymorphismhas effect on the airway inflammation of COPD. Methods A total of 312 COPD patients were recruited for this study. Four polymorphic loci ( T2, T1, S2, and Q-1) of ADAM33 were selected for genotyping by using the polymerase chain reaction-restriction fragment length polymorphism ( PCR-RFLP) method. Total and differential cell counts, contents of TNF-α, IL-6, IL-8, and VEGF in induced sputumwere detected. The relationship between genotypes and inflammatory reaction was analyzed. Results On locus T2, the cell counts and content of TNF-αin induced sputum increased significantly in the carriers with GG genotype than those with AA and AG genotypes ( Plt;0.01 and Plt;0.05) . On locus T1, the lymphocyte counts in induced sputumincreased significantly in the carriers with GG genotype than those with AA and AG genotypes ( Plt;0.05) ; but the content of IL-8 in induced sputumwas higher in AA and AG genotypes ( Plt;0.05) . On locus Q-1, the contents of VEGF and IL-8 in induced sputum increased significantly in the carriers with GG genotype than those with AA and AG genotypes (Plt;0.05) . On locus S2, the total cell counts in induced sputumincreased significantly in the carriers with GG genotype than those with CC and CG genotypes ( Plt;0.05) , and the content of IL-8 in induced sputum increased significantly in GG genotype ( Plt;0.01 ) . Conclusion These results suggest that ADAM33 polymorphism may participate the pathogenesis of COPD by promoting airway inflammation.
Objective To investigate the relationship of p53 codon 72 polymorphism and susceptibility to gastric cancer in high incidence area of Hexi area of Gansu province. Methods The Arg/Pro polymorphism of p53 gene was detected by real-time PCR in 140 patients with gastric cancer, 110 patients with gastric precancerous lesion and 125 healthy controls; Helicobacter pylori (Hp) infection was detected by Warthin-Starry silver method． Results The Pro allele frequencies of p53 gene in gastric cancer cases (0.543) were higher than those in gastric precancerous lesion (0.482) and controls (0.472). The Pro genotype had a more than 1.846 fold increased risk of gastric cancer 〔OR=1.846; 95% 〗CI (1.006-3.387); P =0.046〕． With statistical analysis， the genotype of p53 gene was correlated with location and Laurens histological type （ P ＜ 0.05）. A significantly higher risk of gastric cancer was also seen in cases with p53 Pro genotype, food, Hp infection, positive mind factor and positive family history． Conclusion There is a b correlation between the p53 gene codon 72 Arg/Pro polymophism and susceptibility to gastric cancer in Hexi area of Gansu province and the Pro/Pro genotype may be one of the major risk factors in patients with gastric cancer.
ObjectiveTo explore the relationship between hexokinase domain-containing protein 1 (HKDC-1) single nucleotide polymorphism (SNP) and first-line anti-tuberculosis drug-induced liver injury (ATDILI) in tuberculosis patients in western China.MethodsFrom November 2016 to April 2018, 746 tuberculosis patients treated in West China Hospital of Sichuan University were collected and divided into ATDILI group and non-ATDILI group according to the liver function indicators. DNA was extracted by QIAamp? DNA Blood Mini Kit (Qiagen, Germany). Seven SNPs of the HKDC-1 gene were genotyped by high-throughput genotyping technique and the differences between the two groups were compared.ResultsThere were 118 ATDILI and 628 non-ATDILI cases enrolled in this study. In clinical symptoms, the differences in incidences of fever and weight loss between the two groups were statistically significant (P=0.004, 0.024). The C allele at rs906219 was associated with low susceptibility to ATDILI [odds ratio (OR)=0.737, 95% confidence interval (CI) (0.556, 0.957), P=0.033], and the additive model and dominant model showed that CC/CA genotype had a lower risk of ATDILI than AA genotype [CC vs. AA: OR=0.563, 95%CI (0.325, 0.976), P=0.039; CC+CA vs. AA: OR=0.533, 95%CI (0.348, 0.817), P=0.004].ConclusionThe SNP of rs906219 in HKDC-1 is correlated with ATDILI occurrence in tuberculosis patients in western China, which provides clues for personalized anti-tuberculosis treatment.
Objective To investigate the correlation between MDM2 SNP309 and gastric cancer (GC) risk in Eastern Asian population. Methods Two reviewers independently searched MEDLINE, EMbase and CBM (from January 1st, 1990 to October 23rd, 2012) for case-control studies on the correlation between MDM2 SNP309 and GC risk in Eastern Asian population. Two reviewers independently screen literature, extracted the data, and assessed the methodological quality. Then meta-analysis was performed using RevMan 5.0 software. Results 5 case-control studies were finally included involving 1 621 GC cases and 2 639 controls. The pooled results showed that the variant homozygote (309GG genotype) was significantly associated with an increased risk of GC as compared to wild-type homozygote (309TT genotype: OR=1.54, 95% CI 1.04 to 2.29, P=0.02). Nevertheless, no association was found in comparison of variant heterozygote (309TG genotype) between wild-homozygote (309TT genotype: OR=1.03, 95% CI 0.75 to 1.42, P=0.006). A significantly increased risk of GC was observed for the recessive model (GG vs. TT/TG: OR=1.49, 95% CI 1.20 to 1.84, P=0.07). While in the dominant model (GG/TG vs. TT), non-significant association was observed (OR=1.18, 95% CI 0.84 to 1.65, P=0.001). Conclusion The MDM2 309GG may be significantly associated with an increased risk of GC among Eastern Asians.
