ObjectiveTo systematically evaluate the association between MTHFR gene C677T polymorphism and susceptibility to young and middle-aged adult ischemic stroke among Chinese population. MethodsSuch databases as PubMed, EMbase, The Cochrane Library (Issue 11, 2013), CBM, CNKI, VIP and WanFang Data were systemically searched to collect case-control studies published from Jan 1990 to Dec 2013. RevMan 5.2 was used to quantitatively analyzed the qualified and included studies, the pooled odds ratio (ORs) with 95% confidence interval (CI) were calculated; Stata 12.0 software were used for sensitivity and publication bias analysis. ResultsA total of 10 studies were included, which involved 787 cases and 766 controls. The results of meta-analysis showed that, in overall young and middle-aged adult group (aged less than 60), individuals that carried T allele risked more with ischemic stroke than those carried C allele (OR=1.42, 95%CI 1.07 to 1.89, P=0.02); more susceptibility to ischemic stroke was found among people of TT genotype compared with those of CC genotype (OR=2.11, 95%CI 1.58 to 2.81, P=0.00), as well as those of TT+TC genotype compared with CC genotype (OR=1.97, 95%CI 1.55 to 2.51, P=0.00), and those of TT genotype compared with TC+CC genotype (OR=1.42, 95%CI 1.13 to 1.77, P=0.00). Increased risk was also observed in TT+TC genotype compared with CC genotype in young adult subgroup (aged less than 45) (OR=1.66, 95%CI 1.19 to 2.32, P=0.00). ConclusionMTHFR gene C677T polymorphism is significantly associated with susceptibility to young and middle-aged adult ischemic stroke among Chinese population, and more risk may exist in middle-aged adult population.
The association between single nucleotide polymorphism and disease is a typical representation of genetic association studies. Compared with the traditional dichotomous data, single nucleotide polymorphism data has its own characteristics, and 5 genetic models are commonly performed in meta-analysis. In this paper, we show how to use the " meta” package in R software to conduct meta-analysis of single nucleotide polymorphism research through examples.
ObjectiveTo understand the genetics associations between low-density lipoprotein receptor-related protein 5 (LRP5) gene polymorphisms and susceptibility of osteoporosis in patients with chronic obstructive pulmonary disease (COPD).MethodsThree hundred and seventy-nine patients with acute exacerbation of COPD were divided into groups of non osteoporosis and osteoporosis. Genomic DNA was extracted from all patients. UCSC genome browser and Haploview 4.2 software were used to screen tag single nucleotide polymorphisms (tagSNP) of LRP5 gene. The tagSNP was genotyped by Sequenom MassARRAY SNP detection method. Logistic regression were used to analysis the odds ratio (OR) values and confidence intervals (CI) of each SNP in different genetic models to assess the association between single nucleotide polymorphisms in LRP5 gene and osteoporosis in COPD patients.ResultsEight tagSNPs of LRP5 gene (rs312016 T/C, rs312017 C/T, rs312018 A/G, rs3736228 C/T, rs901823 T/C, rs589963 G/A, rs638051 A/G, rs671494 C/A) were selected for association analysis. Patients of rs901823 carrying C/C genotype had a higher risk of osteoporosis than those carrying T/T and C/T genotypes in COPD patients (in recessive mode, C/C vs. T/T+C/T, OR=9.42, 95%CI=2.01–44.29), P=0.000 431 8).ConclusionsThere is a significant association between rs901823 of LRP5 gene and osteoporosis in patients with COPD. Further studies are needed to discover the mechanism of LRP5 gene polymorphism in the pathogenesis of osteoporosis in COPD patients.
Objective To explore the relationship between alcohol induced osteonecrosis of the femoral head (ONFH) and the single nucleotide polymorphisms (SNP) of methylene tetrahydrofolate reductase (MTHFR) 677 C/T. Methods From July 2005 to May 2008, eighty-nine male patients with alcohol induced ONFH were selected as the patient group, aged from 24 to58 years old (mean 44.3 years old). The time of drinking was about 17 years, 375 mL/day. The imaging evidence showed ONFH with no other history associated to ONFH. Seventy-seven male healthy adults were selected as the control group, aged from 23 to 52 years old (mean 42.7 years old). The time of drinking was about 14 years, 335 mL/day. The imaging evidence showed no ONFH. The 2 mL blood sample was acquired from every subject. DNA was purified from leucocyte at first, then was ampl icated by PCR, the product of PCR was sequenced at last. The SNP of MTHFR 677 C/T was analyzed with SPSS 12.0 software package. Results The TT genotype and T allele frequencies of MTHFR 677 C/T were 27.2% and 52.0% (P gt; 0.05) in the control group, and the distribution of genotype was consistent with Hardy-Weinberg equil ibrium. The genotype frequencies of CC, CT and TT were 23.4% (18 cases), 49.4% (38 cases) and 27.2% (21 cases) in the control group, were 14.6% (13 cases), 36.0% (32 cases) and 49.4% (44 cases) in the patient group; showing statistically significant differences (P lt; 0.05). The allele frequencies of C and T were 48.0% (74) and 52.0% (80) in the control group, and were 32.6% (58) and 67.4% (120) in the patient group; showing statistically significant differences (P lt; 0.05). The frequencies of C, T alleles and TT genotype were higher in the patient group than in the control group, showing statistically significant differences (P lt; 0.05). The odds ratios were 0.523, 1.914 and 2.607, respectively; the 95% confidence interval were 0.335-0.816, 1.226-2.987, 1.359-5.001, respectively. Conclusion The relationship may exist between the SNP of MTHFR 677 C/T and alcohol induced ONFH.
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 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.
Objective To review the research progress of bone morphogenetic protein (BMP) and the liability of ossification of the posterior longitudinal ligament (OPLL). Methods Recent literature concerning BMP and the liability of OPLL was reviewed, analysed, and summarized. Results The single nucleotide polymorphisms (SNPs) of BMP gene may produce a minor cumulative effect and increase individual susceptibility to OPLL. A variety of environmental factors can promote the occurrence and development of OPLL by increasing the expression of BMP gene. Conclusion The SNPs of BMP gene may increase individual susceptibility to OPLL. However, interaction of cumulative effect of the SNPs and environmental factors can promote the liability to OPLL.