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).
After adjusting for multiple covariates, SNPs in or near CDKAL1, CDKN2BAS, KCNQ1, TCF7L2, CDC123/CAMK1D, HHEX, and TCF2 were associated with the risk for lean T2D, and SNPs in or near KCNQ1 and FTO were associated with the risk for obese T2D.
Although we found no evidence of widespread non-additive genetic effects contributing to obesity and type 2 diabetes risk, we did find robust examples of recessive effects at the FTO and CDKAL1 loci.
Genetic variants of WFS1, CDKAL1, CDKN2BAS, TCF7L2, HHEX, KCNQ1, TSPAN8/LGR5, FTO, and TCF2 were associated with the risk for T2D with MetS, as well as the risk for development of T2D with at least one of the MetS components (P < 0.05).
We further evaluated the cumulative effect on type 2 diabetes of these 4 SNPs, in combination with 5 SNPs at HHEX, CDKAL1, VEGFA and FTO reported previously.
The mRNA expression level of FTO was significantly higher in T2DM patients than that of the controls (P = .0007) and was associated with the risk of T2DM (odds ratio 2.797, 95% confidence interval 1.452-5.389, P = .002).
Using MGA, some common gene variants were found to have little (<5%) but significant impact on the heritability of T2D related QTs [KCNJ11 (rs5219), p=0.004]; [IGF2BP2 (rs4402960), p=0.02]; [SLC30A8 (rs13266634), p=0.05]; [CAPN10 (rs2975760), p=0.031]; [FTO (rs8050136), p=0.023]; [FTO (rs9939609), p=0.018] and [SLC30A8 (rs13266634), p=0.05].
The methods are illustrated through meta-analysis of interaction between Single Nucleotide Polymorphisms in FTO gene and body mass index on high-density lipoprotein cholesterol data from a set of eight studies of type 2 diabetes.
The fat mass and obesity-associated gene (FTO) rs9939609 and peroxisome proliferator-activated receptor gamma 2 gene (PPARG2) rs1801282 polymorphisms are type 2 diabetes mellitus susceptibility gene variants associated with obesity.
Assaying 9 selected SNPs in 4 Asian-descent populations--Japanese, Vietnamese, Sri Lankan and Chinese (n≤26,109 for BMI association and n≤24,079 for type 2 diabetes association), we identified a responsible haplotype tagged by a cluster of SNPs and successfully narrowed the list of potential causal variants to 25 SNPs, which are the smallest in number among the studies conducted to date for FTO.
While loss-of-function mutation in FTO causes a recessive lethal syndrome, sequence variants in introns of the FTO gene are associated with obesity and type 2 diabetes.
Further meta-analysis pooling 20 studies in Han Chinese confirmed the association of 10 genetic variants in IGF2BP2, CDKAL1, JAZF1, SCL30A8, HHEX, TCF7L2, EXT2, and FTO genes with T2DM.
The Fat Mass and Obesity-Associated Protein (FTO) gene rs9939609 single nucleotide polymorphism (SNP) has been associated with obesity, metabolic syndrome, insulin resistance (IR), and type 2 diabetes mellitus in the general population.
The attenuation of FTO-T2DM risk on BMI adjustment reinforces that BMI does not fully account for the adiposity effects among Asian Indians who are more centrally obese.
In the meta-analysis of 42 studies for 11 obesity/BMI-associated loci, we observed a statistically significant association of the FTOrs9939609 polymorphism (66 425 T2D cases/239 689 normoglycaemic subjects; P = 1·00 × 10(-41) ) and six other variants with T2D risk (17 915 T2D cases/27 531 normoglycaemic individuals: n = 40 629-130 001; all P < 0·001 for SH2B1 rs7498665, FAIM2 rs7138803, TMEM18 rs7561317, GNPDA2 rs10938397, BDNF rs925946 and NEGR1 rs2568958).
Genome-wide association studies (GWAS) have reproducibly associated variants within introns of FTO with increased risk for obesity and type 2 diabetes (T2D).
This paper presents current knowledge about the role of FTO gene in the development of obesity and type 2 diabetes in different ethnic groups and the association between FTO polymorphism and lifestyle modifications predisposing to adiposity.
This was a cross-sectional study of 236 patients with type 2 diabetes (age 60.0 ± 10.3 years; diabetes duration 12.7 ± 8.2 years; 53.4% females) who were genotyped for FTOrs9939609.
This study aimed to investigate the association of FTOrs9939609 and MC4R rs17782313 with anthropometric indexes, BP, and type 2 diabetes mellitus among hypertensive patients.