Analysis of the obesity gene FTO in 14,803 type 1 diabetes cases and controls.
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ABSTRACT:
SUBMITTER: Field SF
PROVIDER: S-EPMC2151140 | biostudies-literature | 2007 Oct
REPOSITORIES: biostudies-literature
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Analysis of the obesity gene FTO in 14,803 type 1 diabetes cases and controls.
Field S F SF Howson J M M JM Walker N M NM Dunger D B DB Todd J A JA
Diabetologia 20070727 10
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Project description:BackgroundFTO is a gene located in chromosome region 16q12.2. Recently two studies have found associations of several single nucleotide polymorphisms (SNPs) in FTO with body mass index (BMI) and obesity, particularly rs1421085, rs17817449, and rs9939609.MethodsWe examined these three SNPs in 583 extremely obese women with current BMI greater than 35 kg/m2 and lifetime BMI greater than 40 kg/m2, and 544 controls who were currently normal weight (BMI<25 kg/m2) and had never been overweight during their lifetimes.ResultsWe detected highly significant associations of obesity with alleles in all three SNPs (p < 10-9). The strongest association was with rs1421085 (p = 3.04 x 10-10, OR = 1.75, CI = 1.47-2.08). A subset of 99 cases had extremely discordant sisters with BMI<25 kg/m2. The discordant sisters differed in allele and genotype frequencies in parallel with the overall case and control sample. The strongest association was with rs17817449 (z = 3.57, p = 3.6 x 10-4).ConclusionThese results suggest common variability in FTO is associated with increased obesity risk or resistance and may in part account for differences between closely related individuals.
| S-EPMC2254593 | biostudies-literature
Project description:The objective was to compare the impact of clinical and genetic factors on body mass index (BMI) in children with type 1 diabetes (T1DM) without severe obesity. A total of 1,119 children with T1DM (aged 4-18 years) were qualified to take part in the study. All children were genotyped for variants of FTO, MC4R, INSIG2, FASN, NPC1, PTER, SIRT1, MAF, IRT1, and CD36. Results. Variants of FTO showed significant association with BMI-SDS in the T1DM group. The main factors influencing BMI-SDS in children with T1DM included female gender (P = 0.0003), poor metabolic control (P = 0.0001), and carriage of the A allele of the FTO rs9939609 gene (P = 0.02). Conclusion. Our research indicates, when assessing, the risk of overweight and obesity carriage of the A allele in the rs9939609 site of the FTO gene adds to that of female gender and poor metabolic control. This trial is registered with ClinicalTrials.gov (NCT01279161).
| S-EPMC4156980 | biostudies-literature
Project description:BackgroundFTO, a gene recently discovered in genomewide associated studies for type 2 diabetes mellitus (T2D), play an important role in the management of energy homeostasis, nucleic acid demethylation and regulation of body fat mass by lipolysis. The aim of this study was to analyze the association of FTO rs8050136 A>C genetic variant with clinical and biochemical parameters of T2D in the population of West Balkan region (Bosnians and Herzegovinians and Kosovars).MethodsThe study included 638 patients with T2D and prediabetes and 360 healthy controls of both genders, aged from 40 to 65 years. Patients were recruited at the Clinical Centre University of Sarajevo, University Hospital of Clinical Centre in Banja Luka, General Hospital in Tešanj and Health Centre in Prizren. Genotyping of analyzed FTO polymorphism rs8050136 A>C was performed by qPCR allelic discrimination.ResultsGenotype frequencies of the analyzed polymorphism were comparable between patients with T2D, prediabetic patients, and healthy population. Logistic regression analyses didn't show significant association of FTO rs8050136 A allele with increased risk of T2D. However, risk A allele was significantly associated with higher levels of HbA1c, insulin, HOMA-IR index, diastolic blood pressure, and inflammatory markers (fibrinogen and leukocytes) as well as showed tendency of association with increased values of obesity markers (BMI, waist and hip circumference).ConclusionsResults of our study showed a significant association of FTO genetic variant rs8050136 A>C with the major markers of insulin resistance, obesity and inflammation, opening new avenues for solving many unclear questions in the pathogenesis of T2D.
| S-EPMC6410997 | biostudies-literature
Project description:BACKGROUND:Perilipins are proteins that coat lipid globules in adipocytes, which are steroid-generating cells that play a central role in lipid storage and breakdown. The FTO gene is associated with type-2 diabetes (T2D) and increased fat mass. In this work the association of perilipin and FTO gene polymorphisms in T2D was investigated. METHODS:One hundred eighty-three Iranian men and women with T2D, and 174 healthy controls with no known metabolic diseases, participated in the study. The subjects were genotyped using tetra-primer amplification refractory mutation system-polymerase chain reaction (Tetra-ARMS-PCR) and their clinical traits were analyzed. RESULTS:A significant association was found between the perilipin rs1052700 polymorphism and T2D, and between the FTO rs3751812 polymorphism and obesity (P = 0.03 and 0.003, respectively); however, no significant relationship was found between rs3751812 and T2D. CONCLUSION:The FTO rs3751812 polymorphism is a major genetic determinant of obesity, but not T2D. The perilipin rs1052700 polymorphism is related to T2D but not obesity.
| S-EPMC5643444 | biostudies-literature
Project description:BackgroundObesity and diabetes are major modifiable risk factors for pancreatic cancer. Interactions between genetic variants and diabetes/obesity have not previously been comprehensively investigated in pancreatic cancer at the genome-wide level.MethodsWe conducted a gene-environment interaction (GxE) analysis including 8,255 cases and 11,900 controls from four pancreatic cancer genome-wide association study (GWAS) datasets (Pancreatic Cancer Cohort Consortium I-III and Pancreatic Cancer Case Control Consortium). Obesity (body mass index ≥30 kg/m2) and diabetes (duration ≥3 years) were the environmental variables of interest. Approximately 870,000 SNPs (minor allele frequency ≥0.005, genotyped in at least one dataset) were analyzed. Case-control (CC), case-only (CO), and joint-effect test methods were used for SNP-level GxE analysis. As a complementary approach, gene-based GxE analysis was also performed. Age, sex, study site, and principal components accounting for population substructure were included as covariates. Meta-analysis was applied to combine individual GWAS summary statistics.ResultsNo genome-wide significant interactions (departures from a log-additive odds model) with diabetes or obesity were detected at the SNP level by the CC or CO approaches. The joint-effect test detected numerous genome-wide significant GxE signals in the GWAS main effects top hit regions, but the significance diminished after adjusting for the GWAS top hits. In the gene-based analysis, a significant interaction of diabetes with variants in the FAM63A (family with sequence similarity 63 member A) gene (significance threshold P < 1.25 × 10-6) was observed in the meta-analysis (P GxE = 1.2 ×10-6, P Joint = 4.2 ×10-7).ConclusionsThis analysis did not find significant GxE interactions at the SNP level but found one significant interaction with diabetes at the gene level. A larger sample size might unveil additional genetic factors via GxE scans.ImpactThis study may contribute to discovering the mechanism of diabetes-associated pancreatic cancer.
| S-EPMC7483330 | biostudies-literature
Project description:BackgroundThe pathogenesis of obesity is reportedly related to variations in the fat mass and an obesity-associated gene (FTO); however, as the number of reports increases, particularly with respect to varying ethnicities, there is a need to determine more precisely the effect sizes in each ethnic group. In addition, some reports have claimed ethnic-specific associations with alternative SNPs, and to that end there has been a degree of confusion.MethodsWe searched PubMed, MEDLINE, Web of Science, EMBASE, and BIOSIS Preview to identify studies investigating the associations between the five polymorphisms and obesity risk. Individual study odds ratios (OR) and their 95% confidence intervals (CI) were estimated using per-allele comparison. Summary ORs were estimated using a random effects model.ResultsWe identified 59 eligible case-control studies in 27 articles, investigating 41,734 obesity cases and 69,837 healthy controls. Significant associations were detected between obesity risk and the five polymorphisms: rs9939609 (OR: 1.31, 95% CI: 1.26 to 1.36), rs1421085 (OR: 1.43, 95% CI: 1.33 to 1.53), rs8050136 (OR: 1.25, 95% CI: 1.13 to 1.38), rs17817449 (OR: 1.54, 95% CI: 1.41 to 1.68), and rs1121980 (OR: 1.34, 95% CI: 1.10 to 1.62). Begg's and Egger's tests provided no evidence of publication bias for the polymorphisms except rs1121980. There is evidence of higher heterogeneity, with I2 test values ranging from 38.1% to 84.5%.ConclusionsThis meta-analysis suggests that FTO may represent a low-penetrance susceptible gene for obesity risk. Individual studies with large sample size are needed to further evaluate the associations between the polymorphisms and obesity risk in various ethnic populations.
| S-EPMC3118373 | biostudies-literature
Project description:The single nucleotide polymorphism rs9939609 of the gene FTO, which encodes fat mass and obesity-associated protein, is strongly associated with obesity and type 2 diabetes (T2D) in multiple populations; however, the underlying mechanism of this association is unclear. The present study aimed to investigate FTO genotype-dependent metabolic changes in obesity and T2D. To elucidate metabolic dysregulation associated with disease risk genotype, genomic and metabolomic datasets were recruited from 2,577 participants of the Korean Association REsource (KARE) cohort, including 40 homozygous carriers of the FTO risk allele (AA), 570 heterozygous carriers (AT), and 1,967 participants carrying no risk allele (TT). A total of 134 serum metabolites were quantified using a targeted metabolomics approach. Through comparison of various statistical methods, seven metabolites were identified that are significantly altered in obesity and T2D based on the FTO risk allele (adjusted p < 0.05). These identified metabolites are relevant to phosphatidylcholine metabolic pathway, and previously reported to be metabolic markers of obesity and T2D. In conclusion, using metabolomics with the information from genome-wide association studies revealed significantly altered metabolites depending on the FTO genotype in complex disorders. This study may contribute to a better understanding of the biological mechanisms linking obesity and T2D.
| S-EPMC4889059 | biostudies-literature
Project description:Type 2 diabetes mellitus (T2DM) is growing in an epidemic manner across the world and India has the world's largest number of diabetic subjects. The present study was carried out to investigate the association of glutathione-S-transferase (GSTM1, GSTT1) and fat mass and obesity associated (FTO) gene polymorphisms with T2DM patients and controls, and its role in increasing the susceptibility to T2DM. A total of 198 subjects (101 T2DM patients and 97 controls) participated in this study. GSTM1, GSTT1 and FTO gene polymorphisms in the patients and controls were evaluated by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). We observed significant association of GSTM1 positive (p = 0.046) and GSTM1 null (p = 0.046) genotypes with T2DM, while no significant association was found with the FTO gene polymorphism in our study. It seems that the GSTM1 gene polymorphism can be a predictive marker for early identification of a population at risk of T2DM. The potential role of GST and FTO gene polymorphisms as a marker of susceptibility to T2DM needs further studies in a larger number of patients.
| S-EPMC4347477 | biostudies-literature
Project description: Not available
| S-EPMC2151139 | biostudies-literature
Project description:Recent multi-dimensional approaches to the study of complex disease have revealed powerful insights into how genetic and epigenetic factors may underlie their aetiopathogenesis. We examined genotype-epigenotype interactions in the context of Type 2 Diabetes (T2D), focussing on known regions of genomic susceptibility. We assayed DNA methylation in 60 females, stratified according to disease susceptibility haplotype using previously identified association loci. CpG methylation was assessed using methylated DNA immunoprecipitation on a targeted array (MeDIP-chip) and absolute methylation values were estimated using a Bayesian algorithm (BATMAN). Absolute methylation levels were quantified across LD blocks, and we identified increased DNA methylation on the FTO obesity susceptibility haplotype, tagged by the rs8050136 risk allele A (p?=?9.40×10(-4), permutation p?=?1.0×10(-3)). Further analysis across the 46 kb LD block using sliding windows localised the most significant difference to be within a 7.7 kb region (p?=?1.13×10(-7)). Sequence level analysis, followed by pyrosequencing validation, revealed that the methylation difference was driven by the co-ordinated phase of CpG-creating SNPs across the risk haplotype. This 7.7 kb region of haplotype-specific methylation (HSM), encapsulates a Highly Conserved Non-Coding Element (HCNE) that has previously been validated as a long-range enhancer, supported by the histone H3K4me1 enhancer signature. This study demonstrates that integration of Genome-Wide Association (GWA) SNP and epigenomic DNA methylation data can identify potential novel genotype-epigenotype interactions within disease-associated loci, thus providing a novel route to aid unravelling common complex diseases.
| S-EPMC2987816 | biostudies-literature