PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Association analysis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources

The association between GLP-1R expression and cardiovascular-kidney-metabolic-related diseases in non-diabetic and non-obese population: evidence triangulation using Mendelian randomization, observational and polygenic score association analysis.

BACKGROUND: Glucagon-like peptide-1 receptor (GLP-1R) agonists are emerging as promising therapies for cardiovascular-kidney-metabolic (CKM) related diseases in individuals with type 2 diabetes mellitus (T2DM) or obesity. But their effects in non-obese and non-diabetic individuals are unclear. This study triangulates evidence using Mendelian randomization (MR), polygenic scores (PGS) and observational analyses to estimate the associations of GLP-1R expression with chronic kidney disease (CKD), heart failure (HF) and metabolic dysfunction-associated steatotic liver disease (MASLD). METHODS: For the MR analysis, instruments mimicking GLP-1R expression were identified using pancreas-specific cis-expression quantitative trait loci from GTEx (N ≤ 305). MR-Robust method was used as the primary MR approach. PGS and observational analyses were performed both in non-diabetic and non-obese individuals separately. A genome-wide association study (GWAS) for MASLD (14,231 cases and 348,091 controls) was performed in the general population using data from UK Biobank. RESULTS: GLP-1R expression showed robust effects on CKD (odds ratio [OR] 0.96, 95%CI 0.95 to 0.97, q = 1.7 × 10- 10 ), HF (OR = 0.96, 95%CI 0.94 to 0.97, q = 2.5 × 10- 8) and MASLD (OR = 0.96, 95%CI 0.93 to 0.98, q = 1.3 × 10- 3) in the general population. Consistent results were observed in validation analyses. Furthermore, PGS and observational analyses among non-T2DM and non-obese individuals found little evidence to support its association with CKD, HF or MASLD. GWAS analysis identified eight conditionally independent variants associated with MASLD, in which rs563199662 was a new signal located at TFPI region. CONCLUSIONS: This study provides multilayered evidence for GLP-1R expression in mitigating CKD, HF and MASLD risks in the general population, while de-prioritized its effect on CKM-related diseases in non-obese and non-diabetic individuals. Further clinical trials are needed to validate the effects of GLP-1R agonists in relative health population.

Humans↗

Association analysis of genes involved in the leptin-signaling pathway with obesity in Brazil.

OBJECTIVE: To investigate associations of polymorphisms in the LEP, LEPR and NPY genes with obesity-related traits in a Brazilian population of European descent. METHODS: A total of 183 women and 153 men (mean body mass index (BMI), 26.1+/-4.8 kg/m(2)) were genotyped using the PCR-RFLP procedure for the LEP A19G, LEPR Gln223Arg, LEPR PRO1019pro and NPY Leu7Pro polymorphisms. Frequencies were compared among normal-weight and overweight plus obese groups with chi-square tests, mean BMI and waist circumference were compared among genotypes by t-tests and analysis of variance. RESULTS: The genotype and allele frequencies of the LEPR Gln223Arg polymorphism were significantly different between normal-weight and overweight plus obese groups (P=0.013 and 0.009, respectively). Although there was no difference in the mean adjusted BMI among the three LEPRGln223Arg genotypes, a trend was observed for Arg/Arg individuals to have a higher mean BMI compared to Gln/Gln homozygotes, with heterozygote individuals presenting intermediate mean BMI between the two homozygote groups (ANOVA, P=0.063). However, in non-smokers, the LEPR Gln223Arg polymorphism showed a highly significant effect over BMI (P=0.009). When the analysis was restricted to premenopausal women, a highly significant effect of NPY was observed. Women bearing the Pro variant presented a lower BMI than wild-type homozygotes (P=0.001). CONCLUSION: Our findings suggest that genetic variability in the leptin receptor and neuropeptide Y genes is implicated in body weight regulation, the LEPR Gln223Arg variant being associated with a BMI increase in this Caucasian population, especially in non-smokers, while the NPY Leu7Pro polymorphism was associated with BMI reduction in premenopausal women.

Adult↗

Association analysis of NOTCH4 loci in schizophrenia using family and population-based controls.

A genetic association between NOTCH4 and schizophrenia has previously been proposed. Unsing all markers previously shown to be associated, we found no evidence for such in three independent family-based samples (n=519 parent-offspring trios), and a case-control sample derived from the same ethnic background as the original observation. These data strongly suggest that NOTCH4 is not a significant susceptibility allele for schizophrenia.

Case-Control Studies↗

Association analysis of serotonin 2A receptor gene T102c polymorphism and schizophrenia.

The serotonin neurotransmitter has been associated with the pathogenesis of mood disorders and schizophrenia. Serotonin receptors genes may therefore be candidate genes for the study of the genetics of these disorders. In this study, patients with schizophrenia (n=235) and controls (n=344) were analysed to determine the correlation between the 5HT(2A) receptor gene T102C polymorphism and schizophrenia. No association was found between the studied polymorphism and schizophrenia (p=0.854 for alleles and p=0.945 for genotypes). Results were also not significant when analysed by gender (for male p=0.861-allele frequency and p=0.467-genotype frequency, for female p=0.857-allele frequency and p=0.833-genotype frequency). Subgroups with regard to schizophrenia subtypes, age of onset and clinical course of schizophrenia were analysed with negative results.

Adult↗

Association analysis between two functional dopamine D2 receptor gene polymorphisms and schizophrenia.

The dopamine D2 receptor (DRD2) gene has been listed as one of the candidate genes for susceptibility to schizophrenia. To date, a significant association between schizophrenia and two functional DRD2 gene polymorphisms, Ser311Cys and -141C Ins/Del, in Japanese samples, has been reported by Arinami et al. [1994: Lancet 343:703-704; 1997: Hum Mol Genet 6:577-582]. In the present study, we replicated the findings of Arinami et al. [1994: Lancet 343:703-704; 1997: Hum Mol Genet 6:577-582] in the same ethnic groups (Japanese samples) with the same polymorphisms (Ser311Cys and -141C Ins/Del). We genotyped these two polymorphisms for 241 patients and for 201 controls. Neither polymorphism was associated with schizophrenia. Moreover, in a haplotype analysis of the present sample, combined pairs of two polymorphisms provided no evidence for the association of either haplotype with schizophrenia. Our findings indicate that an association between the two functional DRD2 gene polymorphisms, Ser311Cys and -141C Ins/Del, and schizophrenia is unlikely.

Aged↗

Association analysis of CHMP1.5 genetic variation and bipolar disorder.

OBJECTIVES: The18p11.2 region surrounding the G-olf gene has been linked in several independent studies to bipolar disorder and schizophrenia, yet association studies between G-olf genetic variations and bipolar disorder have been negative. We hypothesized that the linkage in this region might be due to a gene in close physical proximity to G-olf, and we examined variations in the CHMP1.5 gene within intron 5 of G-olf for association with bipolar disorder. METHODS: Two single-nucleotide polymorphisms, rs1786581 and rs1249624, were analyzed for association with bipolar disorder in 402 unrelated bipolar individuals and 181 unrelated controls. Genotyping was performed via pyrosequencing and restriction fragment length polymorphism analysis; results were compared by chi2 contingency analysis. RESULTS: No evidence was found for association of either allele at rs1249624 with bipolar disorder (chi2=1.25, degrees of freedom=1, P=0.26); however, a trend towards association with the 'T' allele at rs1786581 and with the 'T/T' 1786581/1249624 haplotype was observed. The chi2 for the haplotype was 7.16, (degrees of freedom=3, P=0.067) and for rs1786581 chi2=3.56, degrees of freedom=1, P=0.060; these differences are not statistically significant. CONCLUSIONS: Variation in the CHMP1.5 gene does not appear to be associated with bipolar disorder. A systematic assessment of genetic variation in the region using association studies will be necessary.

3' Untranslated Regions↗

Large scale association analysis for identification of genes underlying premature coronary heart disease: cumulative perspective from analysis of 111 candidate genes.

BACKGROUND: to date, only three groups have reported data from large scale genetic association studies of coronary heart disease using a case control design. METHODS AND RESULTS: to extend our initial report of 62 genes, we present data for 210 polymorphisms in 111 candidate genes genotyped in 352 white subjects with familial, premature coronary heart disease (onset age for men, 45; for women, 50) and a random sample of 418 population based whites. Multivariate logistic regression analysis was used to compare the distributions of genotypes between cases and the comparison group while controlling for age, sex, body mass, diabetes, and hypertension. Significant associations were found with polymorphisms in thrombospondin-4 (THBS4), thrombospondin-2 (THBS2) and plasminogen activator inhibitor-2 (PAI2), the strongest being with the A387P variant in THBS4 (p = 0.002). The THBS2 and THBS4 associations have since been replicated. We evaluated polymorphisms in 40 genes previously associated with coronary heart disease and found significant (p<0.05) associations with 10: ACE, APOE, F7, FGB, GP1BA, IL1RN, LRP1, MTHFR, SELP, and THPO. For five of these genes, the polymorphism associated in our study was different from that previously reported, suggesting linkage disequilibrium as an explanation for failure to replicate associations consistently across studies. We found strong linkage disequilibrium between polymorphisms within and between genes, especially on chromosome 1q22-q25, a region containing several candidate genes. CONCLUSIONS: despite known caveats of genetic association studies, they can be an effective means of hypothesis generation and complement classic linkage studies for understanding the genetic basis of coronary heart disease.

Adult↗

An association analysis between ApoA1 polymorphisms and the high-density lipoprotein (HDL) cholesterol level and myocardial infarction (MI) in Japanese.

Association studies were performed to confirm the effect of polymorphisms in apolipoprotein A1 ( ApoA1) on the high-density lipoprotein cholesterol (HDL-C) level and the incidence of myocardial infarction (MI). A sequence analysis identified nine polymorphisms in ApoA1. After considering linkage disequilibrium, four polymorphisms in ApoA1 and four polymorphisms in the 5'-flanking regions and 3'-flanking regions from the JSNP database were determined in 1,880 subjects recruited from the Suita study, which represents the general population in Japan. Of the eight polymorphisms tested, the ApoA1 T84C polymorphism had the greatest effect on the levels of HDL-C ( P=0.0005, P(c)=0.0040 corrected by the Bonferroni method) and triglyceride ( P<0.0001, P(c)=0.0008). The ApoA1 MspI polymorphism was not associated with HDL-C or triglyceride levels. We confirmed that the ApoA1 T84C polymorphism was associated with the HDL-C level but not the triglyceride level in patients with MI ( n=637). Moreover, this polymorphism was associated with the incidence of MI in male subjects ( P=0.0326). A logistic analysis indicated that the frequency of MI in the CC genotype was lower than that in the CT+TT genotype ( P=0.0145, OR=0.4955, 95% CI: 0.2746-0.8525). The ApoA1 T84C polymorphism is an important marker for the HDL-C level and may be a new risk marker for MI in Japanese.

Aged↗

Family based association analysis of the IL2 and IL15 genes in allergic disorders.

Allergic diseases affect an increasing number of individuals and are a major global health problem. A substantial genetic contribution in the aetiology of allergic diseases is well documented. We have previously reported linkage of allergic diseases and atopy to the region harbouring the IL2 gene (4q27). IL15 is located approximately 20 Mb distal to IL2. The two genes encode cytokines that are structurally and functionally related, both inducing T-cell activation and proliferation. We screened the two genes for sequence variation and applied the seven single-nucleotide polymorphisms (SNPs) identified in a family based association study of two Danish samples comprising a total of 235 families with allergic diseases. None of the IL15 SNPs showed significant association and the haplotype analysis yielded inconsistent results in the two samples. In contrast, the two IL2 SNPs showed association both separately and in haplotypes with several atopic phenotypes, most significantly with IgE-mediated allergy. (single SNP P-value 0.0005 for positive skin prick test, haplotype P-value 0.019 for positive RAST test). To our knowledge, this is the first study reporting association between IL2 and IgE-mediated allergy, asthma and atopic eczema. The SNP (rs2069762) that showed the most consistent results is located in the promoter and has previously been shown to influence the level of IL2 expression. We suggest that the observed overtransmission of the T allele of this SNP may convey increased susceptibility to allergic disease by skewing the Th1/Th2 balance towards Th2.

DNA Primers↗

Association analysis of the DRD4 and COMT genes in methamphetamine abuse.

We analyzed two polymorphisms in genes encoding proteins of the dopamine system, the Val158Met polymorphism in the catechol-O-methyltransferase gene and the 120-bp VNTR polymorphism in the promoter of the dopamine D4 receptor gene for association with methamphetamine abuse. We used a case/control design with 416 methamphetamine abusing subjects and 435 normal controls. All subjects were Han Chinese from Taiwan. We found an excess of the high activity Val158 allele in the methamphetamine abuser group, consistent with several previous reports of association of this allele with drug abuse. The 120-bp VNTR polymorphism in the promoter of the dopamine D4 receptor gene itself did not show significant association with methamphetamine abuse. However, analysis of the 120-bp VNTR polymorphism and the exon 3 VNTR in the dopamine D4 receptor as a haplotype showed significant association with methamphetamine abuse, which gave an empirical P value 0.0034 for a heterogeneity model. Moreover, there were significant interactive effects between polymorphisms in the catechol-O-methyltransferase and dopamine D4 genes. The evidence of interaction between COMT 158 Val/Met and DRD4 48-bp VNTR polymorphisms (P = 0.0003, OR = 1.45, 95% CI: 1.148-1.77), and between COMT 158 Val/Met and DRD4 120 bp promoter polymorphisms (P = 0.01, OR = 1.10, 95% CI: 1.10-1.18) were significant but the latter was weak. We conclude that genetic variation in the dopamine system may encode an additive effect on risk of becoming a methamphetamine abuser.

Adolescent↗

Association analysis between dopamine receptor genes and bipolar affective disorder.

We have performed a case-control analysis of dopamine D2-like receptor (DRD2, DRD3 and DRD4) gene polymorphisms in 118 Han Chinese cases with bipolar affective disorder and 196 control subjects, and replication analysis in 157 English cases and 143 control subjects. We found association between a functional DRD2 promoter variant (P = 0.03 by allele) and the DRD2 taq1A polymorphism (P = 0.001 by allele) in Chinese bipolar disorder patients. However, this finding was not replicated in the Caucasian subjects, indicating that the significant association we observed in the Chinese population is a false positive finding. An alternative explanation is that these polymorphisms are risk factors in Chinese but not Caucasian populations, a hypothesis which seems unlikely in view of the similarity of the clinical characteristics of bipolar disorder in the two populations. We also report a novel, rare one-repeat variant of the DRD4 exon 3 VNTR repeat in Chinese populations, which appears to be absent in Caucasians and is not associated with disease.

Adult↗

Assessment of the new proliferation marker MIB1 in breast carcinoma using image analysis: associations with other prognostic factors and survival.

The 'growth fraction' of tumours can now be assessed on paraffin sections of tissues using the monoclonal antibody MIB1 by a microwave antigen retrieval technique. The MIB1 labelling index was studied using a CAS 200 image analyser in 177 tumours from women with primary operable breast carcinoma in whom long-term follow-up data were known. Statistical analysis showed a strong association between the MIB1 labelling index and histological grade (P < 0.001), tumour size (P = 0.002), tumour type (P < 0.001) and also patient survival (P < 0.001). No association with lymph node stage (P = 0.974) or regional recurrence (P = 0.185), the presence or absence of distant metastases (P = 0.418), patient age (P = 0.309), menopausal status (P = 0.181) or oestrogen receptor status (P = 0.401) was found in this group of patients. In multivariate analysis for survival, when histological grade, lymph node stage and tumour size were included as well as the MIB1 labelling index, each was found to be of independent significance. If histological grade was not included, MIB1 replaced it as the most important variable predicting for survival in this group of patients. The results suggest that the tumour growth fraction, as assessed by the MIB1 labelling index, is an important predictor of survival.

Antibodies, Monoclonal↗

Association analysis between the human interleukin 1beta (-511) gene polymorphism and susceptibility to febrile convulsions.

Recently, an association between a regulatory polymorphism in the gene encoding the pro-inflammatory cytokine interleukin (IL)-1beta and febrile convulsions (FC) has been reported. In this study we attempted to confirm these findings in a sample consisting of 99 FC patients and 126 ethnically matched controls. Since about 3% of all FC patients experience unprovoked seizures (epilepsy) later during life we furthermore genotyped 43 patients with non-lesional temporal lobe epilepsy who reported a history of FC. In both samples we failed to show an association between the IL-1beta polymorphism and an increased risk for FC. We only found a trend towards an increased frequency and carriage of the putative IL-1beta susceptibility allele two in a sub-sample of 43 FC patients who reported a positive family history for seizures in first and/or second degree relatives. However, these trends did not reach statistical significance.

Disease Susceptibility↗

Association analysis of exonic variants of the gene encoding the GABAB receptor and alcohol dependence.

The present association study tested whether genetic variation of the GABAB receptor (GABABR1) gene confers vulnerability to alcohol dependence. The genotypes of three DNA sequence variants in exons 1a1, 7 and 11 of the GABABR1 gene were assessed in 234 German controls and 350 German alcohol-dependent subjects, including three more homogeneous subgroups of alcoholics, marked by (1) history of parental alcoholism (n = 121); (2) history of alcohol withdrawal seizure or delirium (n = 108); and (3) comorbidity of dissocial personality disorder (n = 60). The allele frequencies of none of the investigated GABABR1 variants differed significantly between the controls and the groups of alcoholics when a correction for multiple testing was taken into account (P > 0.004). However, trends (P < 0.10) towards an excess of the Ser489 allele of the exon 7 polymorphism were found in the subgroups of alcoholics, and of the common allele of the exon 11 polymorphism in the entire sample of alcoholics (P = 0.032), alcoholics with parental alcoholism (P = 0.084) and the dissocial alcoholics (P = 0.037). Our findings suggest that the investigated GABABR1 variants do not contribute a substantial effect (RR > 3) to the genetic variance of alcohol dependence. Nevertheless, the hints towards potential allelic associations of the exon 7 and 11 polymorphisms with dissocial alcoholism emphasize further studies to test more defined phenotype-genotype relationships.

Adult↗

A new and fast nonlinear method for association analysis of biosignals.

In this paper, we present some original theoretical aspects of a fast nonlinear association measure based on the work of Cramér. The features of this new measure--the V measure--when applied to biosignals are also shown using simulated time series. A comparative study with other well-known association measures available in the literature of biosignals is presented. V was found to be twice as fast and more robust to nonlinearities than the classical cross-correlation ratio (r2) and more than 100 times faster than the nonlinear regression coefficient (h2), presenting similar behavior in the presence of nonlinear simulated situations. This new measure is very fast and versatile. It is appropriate to deal with nonlinear relations presenting usually a sharp peak in the association function enabling a high degree of selectivity for maxima detection. It seems to constitute an improvement over linear methods of association which is faster and more robust to the existing nonlinearities. It can be used as an alternative to more complex nonlinear association measures when computational speed is an important feature.

Algorithms↗

Assessment and management of single nucleotide polymorphism genotype errors in genetic association analysis.

Single nucleotide polymorphisms (SNP) may be used in case-control designs to test for association between a marker (the SNP) and a disease. However, such designs usually assume that the genotype data are reported without error. We propose a method, the reduced penetrance model method (RPM) that allows for errors in a case-control design, as compared to the full penetrance model method (FPM), that assumes data are errorless. Pearson's chi 2 applied to a 2 x 2 contingency table is the test statistic considered. Additionally, we provide a likelihood method to estimate error rates using SNP genotype data in CEPH pedigrees. We test our method (RPM) against the standard method (FPM) using simulated data. All SNP loci are assumed to have two alleles, coded 1 and 2. We consider three pairs of error rates, two different sample sizes, and two sets of allele frequencies for the SNP locus. SNP genotype data in two populations are simulated under a null hypothesis (allele frequencies equal in both populations) and under an alternative hypothesis (allele frequencies differ between two populations). The total number of simulations is 24; 12 simulations under the null hypothesis, and 12 simulations under the alternative. The significance level threshold is 5%. For the null case, 9/12 (75%) of the simulations show no increase in type I error under RPM, while 3/12 (25%) show a slight increase (rejecting the null for at most 7% of the replicates). There is no increase in the type I error rate for FPM method, which can also be shown analytically. For the alternative case (power), there is a consistent increase in power for the RPM method as compared to FPM method, and average increase of 0.02 for the simulations considered. When sample sizes are large there is virtually no difference in power between RPM and FPM methods. Also, the RPM method provides consistently more accurate allele frequency estimates for the various populations. Our likelihood method to estimate error rates with CEPH pedigrees provides good estimates on average. The largest difference between a true error rate and our average estimated error rate is 0.006. However, there is a fair amount of variability in the estimates, suggesting the need for multiple experiments or larger numbers of CEPH pedigrees. Researchers may use the methods presented in this paper to (1) estimate error rates for their automated genotyping process, and (2) allow for such errors in association analyses, thereby increasing power to detect differences between allele frequencies in case and control populations when errors are present.

Alleles↗

Intrafamilial and case-control association analysis of D2S152 in insulin-dependent diabetes.

We have performed intrafamilial and case-control association studies to examine the previously reported linkage disequilibrium between D2S152 and a type 1 diabetes susceptibility gene on chromosome 2q31-q33 (IDDM7). Significant linkage disequilibrium was observed in our subset of 47 Florida affected sibpair families (p < 0.02) but not in the other 57 USA families. We were not able to detect any significant associations between IDDM and D2S152 using case-control studies in a Caucasian data set of 270 unrelated diabetic patients and 370 normal controls ascertained from Florida, or in a Chinese data set of 90 patients and 169 normal controls. Our results suggest that linkage disequilibrium between IDDM7 and D2S152 must be very loose.

Alleles↗

[An association analysis of apolipoprotein E genotypes with Alzheimer's disease in Chinese population].

OBJECTIVE: To analyse the association of apolipoprotein E genotypes with Alzheimer's disease in Chinese population. METHODS: Using PCR and restriction enzyme digestion, we have analyzed ApoE allele frequency of Alzheimer's disease (AD) patients and healthy controls. RESULTS: Among the 56 cases of AD, the frequency of ApoE epsilon 2, ApoE epsilon 3, ApoE epsilon 4 are 3 (2.7%), 84 (75.0%), 25 (22.3%) respectively, while in the 67 controls they are 9 (6.7%), 115 (85.8%), 10 (7.5%) respectively. The frequencies of the two groups have significant difference (P < 0.01) and the frequency of ApoE epsilon 4 allele is higher in AD than that in the health controls and the statistical treatment suggest that there is significant difference (chi 2 = 10.99, P < 0.01, OR = 3.59, 95% CI = 1.54-8.41). The frequency of the ApoE epsilon 3 is lower in AD than that in the health controls and the difference is also statistically significant(P < 0.05). CONCLUSIONS: Our results are consistent with previous work in that proving the ApoE epsilon 4 allele is one of the risk factors of AD. The results also provide a support for the protection effect of ApoE epsilon 3 allele in developing AD.

Aged↗