FTO risk haplotype among early onset and severe obesity cases in a population of western Spain

Evidence from a meta-analysis for association of MC4R rs17782313 and FTO rs9939609 polymorphisms with susceptibility to obesity in children

BACKGROUND AND AIM

The aim of this study was to evaluate the association of MC4R rs17782313 and FTO rs9939609 polymorphisms with childhood obesity.

METHODS

A universal search was performed up to May 2021.

RESULTS

A total of 31 studies including 13 studies with 9565 cases and 11956 controls on MC4R rs17782313 and 18 studies with 4789 cases and 15918 controls on FTO rs9939609 were selected.

CONCLUSIONS

Pooled data showed that FTO rs9930506 and MC4R rs17782313 polymorphisms were significantly associated with obesity in children. Stratified analyses revealed that these genetic variants were associated with childhood obesity in Caucasian and Asian children.

ANNORE: Genetic fine mapping with functional annotation

Genome-wide association studies (GWAS) have successfully identified loci of the human genome implicated in numerous complex traits. However, the limitations of this study design make it difficult to identify specific causal variants or biological mechanisms of association. We propose a novel method, AnnoRE, which uses GWAS summary statistics, local correlation structure among genotypes, and functional annotation from external databases to prioritize the most plausible causal SNPs in each trait-associated locus. Our proposed method improves upon previous fine mapping approaches by estimating the effects of functional annotation from genome-wide summary statistics, allowing for the inclusion of many annotation categories. By implementing a multiple regression model with differential shrinkage via random effects, we avoid reductive assumptions on the number of causal SNPs per locus. Application of this method to a large GWAS meta-analysis of body mass index identified six loci with significant evidence in favor of one or more variants. In an additional 24 loci, one or two variants were strongly prioritized over others in the region. The use of functional annotation in genetic fine mapping studies helps to distinguish between variants in high LD, and to identify promising targets for follow-up studies.

Extreme Downregulation of Chromosome Y and Cancer Risk in Men

BACKGROUND

Understanding the biological differences between sexes in cancer is essential for personalized treatment and prevention. We hypothesized that the extreme downregulation of chromosome Y gene expression (EDY) is a signature of cancer risk in men and the functional mediator of the reported association between the mosaic loss of chromosome Y (LOY) and cancer.

METHODS

We advanced a method to measure EDY from transcriptomic data. We studied EDY across 47 nondiseased tissues from the Genotype Tissue-Expression Project (n = 371) and its association with cancer status across 12 cancer studies from The Cancer Genome Atlas (n = 1774) and seven other studies (n = 7562). Associations of EDY with cancer status and presence of loss-off function mutations in chromosome X were tested with logistic regression models, and a Fisher's test was used to assess genome-wide association of EDY with the proportion of copy number gains. All statistical tests were two-sided.

RESULTS

EDY was likely to occur in multiple nondiseased tissues (P < .001) and was statistically significantly associated with the EGFR tyrosine kinase inhibitor resistance pathway (false discovery rate = 0.028). EDY strongly associated with cancer risk in men (odds ratio [OR] = 3.66, 95% confidence interval [CI] = 1.58 to 8.46, P = .002), adjusted by LOY and age, and its variability was largely explained by several genes of the nonrecombinant region whose chromosome X homologs showed loss-of-function mutations that co-occurred with EDY during cancer (OR = 2.82, 95% CI = 1.32 to 6.01, P = .007). EDY associated with a high proportion of EGFR amplifications (OR = 5.64, 95% CI = 3.70 to 8.59, false discovery rate < 0.001) and EGFR overexpression along with SRY hypomethylation and nonrecombinant region hypermethylation, indicating alternative causes of EDY in cancer other than LOY. EDY associations were independently validated for different cancers and exposure to smoking, and its status was accurately predicted from individual methylation patterns.

CONCLUSIONS

EDY is a male-specific signature of cancer susceptibility that supports the escape from X-inactivation tumor suppressor hypothesis for genes that protect women compared with men from cancer risk.

Relationship of FTO gene variations with NAFLD risk in Chinese men

Background

Fat mass and obesity-associated (FTO) gene is an obesity susceptibility gene and its relationship with the nonalcoholic fatty liver disease (NAFLD) remains unclear. This study aims to investigate the relationships of FTO gene variations with NAFLD risk in a Chinese male population.

Methods

A 1:2 matched case–control study was performed on 275 cases of NAFLD and 550 controls matched for age. Nine of the FTO gene single nucleotide polymorphisms (SNPs) were genotyped.

Results

Logistic regression analysis found that FTO rs1477196 was significantly associated with the susceptibility to NAFLD in recessive genetic models [unadjusted odds ratio (OR) = 2.52, 95% confidence interval (CI): 1.22–5.19, P = 0.012] and the relativity weakened after further adjustment for body mass index (BMI), uric acid, metabolic syndrome, smoking, and drinking (adjusted OR = 2.18, 95% CI: 0.96–4.99, P = 0.06). In the obese group, the AA + AG genotypes of rs1121980 and rs9940128 were associated with a decreased risk of NAFLD, when compared with the GG genotype, respectively (rs1121980: adjusted OR = 0.62, 95% CI = 0.39–0.99, P = 0.044; rs9940128: adjusted OR = 0.61, 95% CI = 0.38–0.97, P = 0.038). Furthermore, rs1477196 was associated with the severity of NAFLD (OR = 2.95, 95% CI = 1.09–7.94, P = 0.034).

Conclusions

Our results demonstrated that the FTO gene was related to the presence and severity of NAFLD in a Chinese male population, and the relationships of the tested SNPs with NAFLD are most probably mediated by BMI.

Associations of nicotidamide-N-methyltransferase, FTO, and IRX3 genetic variants with body mass index and resting energy expenditure in Mexican subjects

The enzyme nicotidamide-N-methyltransferase (NNMT) regulates adipose tissue energy expenditure through increasing nicotinamide adenosine dinucleotide (NAD⁺) content. NNMT methylates nicotinamide to N¹-methylnicotidamide (MNA-1) using S-adenosyl methionine. The rs694539 NNMT polymorphism is associated with non-alcoholic steatohepatitis, and rs1941404 is associated with hyperlipidemia. The rs1421085 FTO is related to poor eating behaviors, and rs3751723 IRX3 is associated with obesity. To investigate the association of rs694539 and rs1941404 NNMT, rs140285 FTO and rs3751723 IRX3 polymorphisms with MNA-1 concentrations, resting energy expenditure (REE) and BMI, we included clinically healthy Mexican subjects 30 to 50 years old, 100 subjects (35 men/65 women) with BMI > 30 kg/m² and 100 subjects (32 men/68 women) with BMI < 25 kg/m². Glucose, lipid profile, insulin, leptin, acylated ghrelin, and MNA-1 (LC–MS) were quantified. Resting energy expenditure (REE) was estimated using indirect calorimetry with a Fitmate instrument. Genotyping was performed using PCR–RFLP, and allelic discrimination was examined using TaqMan probes. MNA-1 concentrations and REE were significantly higher in obese subjects. Subjects with the rs694539AA NNMT genotype (recessive model) had lower weight, BMI, and REE. BMI showed an association with HDL-C, triglycerides, MNA-1, acetylated ghrelin, leptin, insulin concentrations, HOMA-IR, REE, and rs1421085. Subjects with the TC or CC genotypes of rs1421085 FTO showed 6 kg and 2 units of BMI more than did those with the TT wild type. The CG of the rs1421085 and rs3751723 haplotypes was associated with BMI. These findings showed that BMI was strongly associated with REE, rs1421085 FTO and the CG rs1421085 FTO and rs3751723 IRX3 haplotypes. We used the GMDR approach in obesity phenotype to show the interaction of four SNPs and metabolic variables.

Genetic variants in the fat mass and obesity-associated (FTO) gene confer risk for extreme obesity and modulate adiposity in a Brazilian population

Obesity is a major public health problem worldwide. It has a complex etiology, influenced by environmental and genetic factors. FTO has been recognized as an important genetic factor for obesity development. This study evaluated the contribution of FTO polymorphisms (rs9939609 and rs17817449) for extreme obesity in terms of the period of obesity onset, anthropometric, and biochemical parameters. The haplotype and the combined effects of FTO risk alleles on obesity susceptibility were evaluated. We investigated 169 normal-weight subjects (body mass index, BMI: 22.8 [21.0; 24.0] kg/m²) and 123 extremely obese individuals (BMI: 47.6 [44.1; 53.1] kg/m²). Genotyping was performed by real time PCR. Our results showed a strong association between FTO variants and extreme obesity. Carriers of the AT haplotype had an increased risk for extreme obesity. Gene scores suggested that the risk of developing extreme obesity was increased 1.37-fold per risk allele added. Both polymorphisms also influenced BMI and body weight. Additionally, rs17817449 influenced triglyceride levels. No effect of FTO variants on the period of obesity onset was found. In conclusion, the FTO polymorphisms showed a strong association with development of extreme phenotype of obesity and adiposity modulation in a Brazilian population.

FTO and IRX3 Genes are Not Promising Markers for Obesity in Labrador Retriever Dogs

Obesity is a serious problem in numerous dog breeds, but knowledge of its hereditary background is scarce. On the contrary, numerous DNA polymorphisms associated with human obesity have been identified, with the strongest effect being demonstrated for FTO gene. We used targeted next-generation sequencing (tNGS) to search for polymorphisms in the region harboring FTO and IRX3 in 32 Labrador dogs. Moreover, we investigated the selected regions of FTO and IRX3, orthologous to the human regions associated with obesity, in 165 Labradors. For all dogs, the following information was available: age, sex, gonadal status, body weight, and body conformation score (BCS). The use of tNGS revealed 12,217 polymorphisms, but none of these obtained significance when lean and obese dogs were compared. Study of two SNPs in the 5’-flanking region of FTO in 165 dogs – creating two upstream reading frames (uORFs) – also showed no association with body weight and BCS but suggested the need for improvement in FTO annotation. No polymorphism was found in the 5’UTR of IRX3. Additionally, no differences of CpG islands methylation status between lean and obese dogs were found. Our study suggests that FTO and IRX3 are not useful markers of obesity in Labrador dogs.

The effect of copy number variations in chromosome 16p on body weight in patients with intellectual disability

Syndromic monogenic obesity is a rare and severe early-onset form of obesity. It is characterized by intellectual disability, congenital malformations, and/or dysmorphic facies. The diagnosis of patients is challenging due to the genetic heterogenicity of this condition. However, the use of microarray technology in combination with public databases has been successful on genotype-phenotype correlations, especially for body mass index (BMI) alteration. In this study, the relationship between copy number variations (CNVs) detected by microarray mapping on 16p region and BMI alterations in syndromic patients were assessed. In order to achieve this goal, 680 unrelated Spanish children with intellectual disability were included. 16p region was characterized by using microarray platforms. All detected variants were classified as: (I) one previously non-described 10-Mb duplication in 16p13.2p12.3 region considered causal of intellectual disability and severe overweight, and (II) eleven 16p11.2 CNVs of low prevalence but with recurrence in syndromic patients with severe BMI alteration (nine proximal and two distal). Proximal 16p11.2 CNVs have a dose-dependent effect: underweight in carriers of duplication and obesity in carriers of deletion. KCTD13 was identified as a possible candidate gene for BMI alteration on proximal syndromes, whereas SH2B1 gene was identified as candidate for distal syndromes. The results shown in this paper suggest that syndromic patients could constitute a reliable model to evaluate hypothalamic satiety and obesity disorders as well as generate a wide expectation for primary prevention of comorbidities. Furthermore, 16p13.2p12.3 showed to be an important region on the regulation of body fatness.

The FTO rs9939609 polymorphism and obesity risk in teens: Evidence-based meta-analysis

OBJECTIVE

This meta-analysis aims evaluate the association of the polymorphism rs9939609 of FTO with the risk of obesity among children and adolescents, based on the assessment of four genetic models: codominant, dominant, recessive alleles model.

METHODS

Case-control studies, published between the years 2011-2015, were selected from tree available databases (PubMed, Scopus and Web of Science) and were analysed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Thirteen studies were included totalling 15,613 participants, divided into 7311 cases and 8302 controls.

RESULTS

The FTO rs9939609 polymorphism was significantly associated with increased risk of obesity in children and adolescents for homozygous genotypes AA and heterozygous AT (TT vs. AT+AA: OR=0.723, 95% CI 0.629 to 0.832; p<0.0001).

CONCLUSION

This meta-analysis shows that the FTO rs9939609 polymorphism in the gene is a risk factor for obesity in children and adolescents with the presence of the A allele, both homozygous genotype AA situation, as heterozygous AT.

Association of fat mass and obesity-associated and retinitis pigmentosa guanosine triphosphatase (GTPase) regulator-interacting protein-1 like polymorphisms with body mass index in Chinese women

Body mass index (BMI) is the most commonly used quantitative measure of adiposity. It is a kind of complex genetic diseases which are caused by multiple susceptibility genes. The first intron of fat mass and obesity-associated (FTO) has been widely discovered to be associated with BMI. Retinitis pigmentosa GTPase regulator-interacting protein-1 like (RPGRIP1L) is located in the upstream region of FTO and has been proved to be linked with obesity through functional tests. We carried out a genetic association analysis to figure out the role of the FTO gene and the RPGRIP1L gene in BMI. A quantitative traits study with 6,102 Chinese female samples, adjusted for age, was performed during our project. Among the twelve SNPs, rs1421085, rs1558902, rs17817449, rs8050136, rs9939609, rs7202296, rs56137030, rs9930506 and rs12149832 in the FTO gene were significantly associated with BMI after Bonferroni correction. Meanwhile, rs9934800 in the RPGRIP1L gene showed significance with BMI before Bonferroni correction, but this association was eliminated after Bonferroni correction. Our results suggested that genetic variants in the FTO gene were strongly associated with BMI in Chinese women, which may serve as targets of pharmaceutical research and development concerning BMI. Meanwhile, we didn't found the significant association between RPGRIP1L and BMI in Chinese women.

Complex Relationship between Obesity and the Fat Mass and Obesity Locus

In the 21st century, obesity has become a serious problem because of increasing obese patients and numerous metabolic complications. The primary reasons for this situation are environmental and genetic factors. In 2007, FTO (fat mass and obesity associated) was the first gene identified through a genome-wide association study (GWAS) associated with obesity in humans. Subsequently, a cluster of single nucleotide polymorphisms (SNPs) in the first intron of the FTO gene was discovered to be associated with BMI and body composition. Various studies have explored the mechanistic basis behind this association. Thus, emerging evidence showed that FTO plays a key role regulating adipose tissue development and functions in body size and composition. Recent prevalent research topic concentrated in the three neighboring genes of FTO: RPGRIP1L, IRX3 and IRX5, as having a functional link between obesity-associated common variants within FTO and the observed human phenotypes. The purpose of this review is to present a comprehensive picture of the impact of FTO on obesity susceptibility and to illuminate these new studies of FTO function in adipose tissue.

Polymorphisms in the SNRPN gene are associated with obesity susceptibility in a Spanish population

BACKGROUND

SNRPN, which codes for the RNA-binding SmN protein, is a candidate gene for Prader-Willi syndrome. One characteristic of this neuroendocrine disorder is hyperphagia resulting in extreme obesity later in life. In the present study, we aimed to assess whether variability within this gene could be implicated in obesity susceptibility.

METHODS

A case-control study was performed including 265 unrelated patients with nonsyndromic and early-onset severe obesity, belonging to high-risk obesity families from Spanish ancestry; 184 healthy control individuals were included representative of the same genetic background and sex-matched. Forty-nine single nucleotide polymorphisms (SNPs) spanning the entire SNRPN gene were selected and genotyped using the Sequenom MassARRAY platform (Sequenom Inc., San Diego, CA, USA).

RESULTS

The four SNPs, rs12905653, rs752874, rs1391516 and rs2047433, were found to be nominally associated with obesity (p < 0.03). The diversity haplotype distribution among cases and controls identified the combination rs12905653-T/rs8028366-A/rs4028395-T as being strongly and inversely associated with obesity (odds ratio = 0.49; p = 0.0006). A genetic risk score was built based on rs12905653, rs1391516 and rs2047433 SNPs and each unit increase in genetic risk score increased the obesity risk by 49% (odds ratio = 1.49, 95% confidence interval = 1.24-1.80).

CONCLUSIONS

To our knowledge, this is the first study reporting an association between variability in the SNRPN gene and the risk of being obese. Interestingly, it was the major allele of each SNP that was found to be associated with the risk of weight gain. Further studies analyzing this locus and the possible additive deleterious capability of SNP combinations could be useful for demonstrating the development of obesity.

FTO rs 9939609 SNP Is Associated With Adiponectin and Leptin Levels and the Risk of Obesity in a Cohort of Romanian Children Population

Obesity is a disorder with increasing frequency in children and adolescents, directly linked with various diseases. Variants in the FTO (fat mass and obesity-related) gene have been associated with body mass index and waist and hip circumferences in widespread populations.The aim of this case-control study was to assess if there is any association between FTO gene variants rs9939609, respectively, rs17817449 with anthropometric and metabolic biomarkers (fasting glucose, TC, HDL-cholesterol, LDL-cholesterol, triglycerides) and adipokines (adiponectin and leptin), in Romanian obese children.A total of 387 children, 201 obese and 186 nonobese individuals, were included in this prospective study. Genotyping of the FTO gene polymorphisms for all subjects was performed using the restriction fragment length polymorphism (PCR-RFLP) method.Significant associations were found between FTO rs9939609 single nucleotide polymorphism (SNP) and obesity. AA genotype carriers have a 2.02 times higher risk for obesity compared with AT+TT genotype carriers. Risk allele carriers of rs17817449 SNP had somewhat higher values of weight, body mass index, waist and hip circumference, total cholesterol, triglycerides, adiponectin, and fasting glucose.This study revealed the genetic association between rs9939609 SNP of FTO and obesity in a Romanian population, and to the authors' knowledge, this is the first study to investigate this association in a Romanian population. This study also established that combined variant genotypes (AA/GG) of FTO rs9939609 /rs17817449 are strongly associated with several measures of adiposity (weight, BMI-SD, mid-upper arm circumference, tricipital skinfold thicknesses) and are also associated with total cholesterol, triglyceride, and LDL-cholesterol levels.

Association of FTO Mutations with Risk and Survival of Breast Cancer in a Chinese Population

Recently, several studies have reported associations between fat mass and obesity-associated (FTO) gene mutations and cancer susceptibility. But little is known about their association with risk and survival of breast cancer in Chinese population. The aim of this study is to examine whether cancer-related FTO polymorphisms are associated with risk and survival of breast cancer and BMI levels in controls in a Chinese population. We genotyped six FTO polymorphisms in a case-control study, including 537 breast cancer cases and 537 controls. FTO rs1477196 AA genotype had significant decreased breast cancer risk [odds ratio (OR) = 0.54, 95% confidence interval (CI): 0.34-0.86] compared to GG genotype, and this association was only found in women with BMI < 24 kg/m(2) (OR = 0.41, 95% CI: 0.22-0.76); and rs16953002 AA genotype conferred significant increased breast cancer risk (OR = 1.80, 95% CI: 1.23-2.63) compared to GG genotype. Haplotype analysis showed that FTO TAC haplotype (rs9939609-rs1477196-rs1121980) had significant reduced breast cancer risk (OR = 0.76, 95% CI: 0.62-0.93) compared with TGC haplotype. But we failed to find any association between FTO polymorphisms and breast cancer survival. These findings suggest that variants in FTO gene may influence breast cancer susceptibility.

Genetic risk profiles for a childhood with severe overweight

OBJECTIVE

The objective of this study was the description of a valid genetic risk score (GRS) to predict individuals with high susceptibility to childhood overweight by their genetic profiles.

DESIGN AND METHODS

Case-control study including a group of children with high-risk familial predisposition to morbid obesity. Birth cohort from general population constituted the validation sample. For the discovery sample, 218 children with non-syndromic obesity and 190 control individuals were included. The validation sample was 653 children from two birth cohorts belonging to the INMA (Infancia y Medio Ambiente [Environment and Childhood] )project. 109 SNPs located in the genes FTO, SEC16B, BDNF, ETV5, SH2B1, GNPDA2, LYPLAL1, MSRA, TFAP2, KCTD15, MTCH2 and NEGR1, previously reported in association to body mass index (BMI) were analysed. For the validation sample, association between genome-wide data and BMI measurements between 3.5 and 5 years of age, were evaluated.

RESULTS

The GRS includes six SNPs in the genes FTO, TFAP2B, SEC16B, ETV5 and SH2B1. The score distribution differs among cases and controls (P = 9.2 × 10(-14) ) showing a significant linear association with obesity (odds ratio [OR] per allele = 1.69; confidence interval [CI] 95% = 1.46-1.97; P = 4.3 × 10(-1) and area under the receiver operating characteristic curve [AUC] = 0.727; CI 95% = 0.676-0.778). The results were validated by the INMA cohort (OR per allele = 1.23 CI 95% = 1.03-1.48 and AUC = 0.601 CI 95% = 0.522-0.680).

CONCLUSIONS

The use of our proposed genetic score provides useful information to determine those children who are susceptible to obesity. To improve the efficiency of clinical prevention and treatment of obesity, it is essential to design individualized based protocols in advance knowledge of the molecular basis of inherited susceptibility.

FTO gene variant and risk of overweight and obesity among children and adolescents: a systematic review and meta-analysis

OBJECTIVE

The fat mass and obesity associated gene (FTO) polymorphisms have been implicated in the susceptibility of overweight/obesity in children and adolescents. However, the results have been inconsistent. In this study, we performed a meta-analysis to clarify the association of FTO gene polymorphisms with overweight/obesity risk among children and adolescents.

METHODS

PubMed and Embase were used to search for eligible published literatures. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random- or fixed-effect models.

RESULTS

A total of 21 articles containing 23 studies (11208cases and 35015controls) were included in our analysis. The results indicated that variant in FTO gene was significantly associated with increased risk of overweight/obesity in children and adolescents (OR=1.35; 95%CI: 1.27-1.44; P<0.001). The overall pooled ORs for risk obesity and overweight were 1.34 (95%CI: 1.21-1.48) and 1.35 (95%CI: 1.25-1.47), respectively. Subgroup analyses also showed similar trends in most subgroups of adjustment for covariates and unadjustment, different ethnicities (Caucasians, Asians, and Amerindians), and each of three investigated polymorphisms (rs9939609, rs1421085, and rs1558902).

CONCLUSIONS

The present meta-analysis suggested a positive association between FTO gene polymorphism and overweight/obesity risk among children and adolescents. Further prospective studies should be recommended to confirm the observed association, and underlying mechanism should be investigated to clarify the association of FTO gene polymorphism with overweight/obesity.

Association of FTO polymorphisms with obesity and obesity-related outcomes in Portuguese children

BACKGROUND

Several studies have reported an association between single nucleotide polymorphisms in the first intron of the FTO gene and body mass index (BMI) or obesity. However, this association has not yet been studied among the Portuguese population. This study aims to assess the association of three FTO polymorphisms (rs1861868, rs1421085 and rs9939609) with obesity-related outcomes in a sample of Portuguese children.

METHODS

We examined a total of 730 children, 256 normal-weight (55.9% girls), 320 overweight (45.3% girls) and 154 obese (53.2% girls), aging from 6 to 12-years-old, recruited randomly from public schools in the central region of Portugal. DNA samples were genotyped for the three polymorphisms by allelic discrimination TaqMan assay. Association of the FTO polymorphisms with several anthropometric traits was investigated. Additionally, we tested association with the risk of obesity using overweight and obese vs. normal-weight children.

RESULTS

We found significant associations of rs9939609 and rs1421085 polymorphisms with weight, BMI, BMI Z-score, waist circumference and hip circumference, even after age and gender adjustment (p<0.05 in all traits). For rs1861868 polymorphism, marginally significant associations were obtained with weight (p = 0.081) and BMI (p = 0.096) after adjustment for age and gender. In case-control studies, both rs9939609 and rs1421085 polymorphisms were significantly associated with obesity (OR 1.97; 95% CI, 1.08-3.59; p = 0.026; OR 2.11; 95% CI, 1.17-3.81; p = 0.013, respectively) but not with overweight (p>0.05). Haplotype analyses identified two combinations (ACA and GCA) associated with a higher risk of obesity (OR 1.53; 95% CI, 1.06-2.22; p = 0.023; OR 1.73; 95% CI, 1.06-2.87; p = 0.030, respectively).

CONCLUSIONS

This study provides the first evidence for the association of FTO polymorphisms with anthropometric traits and risk of obesity in Portuguese children.

Genetic determinants of cardiometabolic risk: a proposed model for phenotype association and interaction

This review provides a translational and unifying summary of metabolic syndrome genetics and highlights evidence that genetic studies are starting to unravel and untangle origins of the complex and challenging cluster of disease phenotypes. The associated genes effectively express in the brain, liver, kidney, arterial endothelium, adipocytes, myocytes, and β cells. Progression of syndrome traits has been associated with ectopic lipid accumulation in the arterial wall, visceral adipocytes, myocytes, and liver. Thus, it follows that the genetics of dyslipidemia, obesity, and nonalcoholic fatty liver disease are central in triggering progression of the syndrome to overt expression of disease traits and have become a key focus of interest for early detection and for designing prevention and treatments. To support the "birds' eye view" approach, we provide a road-map depicting commonality and interrelationships between the traits and their genetic and environmental determinants based on known risk factors, metabolic pathways, pharmacologic targets, treatment responses, gene networks, pleiotropy, and association with circadian rhythm. Although only a small portion of the known heritability is accounted for and there is insufficient support for clinical application of gene-based prediction models, there is direction and encouraging progress in a rapidly moving field that is beginning to show clinical relevance.

Genetic association of SNPs in the FTO gene and predisposition to obesity in Malaysian Malays

The common variants in the fat mass- and obesity-associated (FTO) gene have been previously found to be associated with obesity in various adult populations. The objective of the present study was to investigate whether the single nucleotide polymorphisms (SNPs) and linkage disequilibrium (LD) blocks in various regions of the FTO gene are associated with predisposition to obesity in Malaysian Malays. Thirty-one FTO SNPs were genotyped in 587 (158 obese and 429 non-obese) Malaysian Malay subjects. Obesity traits and lipid profiles were measured and single-marker association testing, LD testing, and haplotype association analysis were performed. LD analysis of the FTO SNPs revealed the presence of 57 regions with complete LD (D' = 1.0). In addition, we detected the association of rs17817288 with low-density lipoprotein cholesterol. The FTO gene may therefore be involved in lipid metabolism in Malaysian Malays. Two haplotype blocks were present in this region of the FTO gene, but no particular haplotype was found to be significantly associated with an increased risk of obesity in Malaysian Malays.