Analysis of association of gene variants with obesity traits in New Zealand European children at 6 years of age

Association of CLOCK gene variants with obesity and adiposity-related anthropometric, metabolic, and behavioral parameters

The CLOCK gene is a core component of the circadian clock and regulates various aspects of metabolism. Therefore, any variation that affects the function/expression of the CLOCK gene may contribute to the manifestation of metabolic disorders such as obesity. This study investigated whether the CLOCK variants rs4864548 and rs6843722 are associated with obesity and related traits in Pakistanis. A total of 306 overweight/obese cases and 306 age- and gender-matched control subjects were recruited (males 336 and females 276, age range 12–63 years). Anthropometric and metabolic parameters were taken by standard procedures and biochemical analyses, respectively. Behavior-related information was collected with a questionnaire. The genotypes of the variants were determined by allelic discrimination Taqman assays. Both variants were found to have a significant association with overweight/obesity according to the over-dominant model. The rs4864548 and rs6843722 were observed to escalate the risk of overweight/obesity by 1.611 ( p = 0.004) and 1.657 ( p = 0.002) times, respectively. These variants were also seen to be significantly associated with various other adiposity-related anthropometric parameters ( p < 0.05). However, no association of both variants with metabolic and behavioral parameters was observed ( p > 0.05). Thus, these variants may contribute to increasing the risk of overweight/obesity and related anthropometric traits in Pakistanis.

Variability in the antioxidant MSRA gene affects the psychopathology of patients with anorexia nervosa

The objective is to determine whether variability in the MSRA gene, related to obesity and several psychiatric conditions, may be relevant for psychopathological symptoms common in Anorexia Nervosa (AN) and/or for the susceptibility to the disorder. A total of 629 women (233 AN patients and 396 controls) were genotyped for 14 tag-SNPs. Psychometric evaluation was performed with the EDI-2 and SCL-90R questionnaires. Genetic associations were carried out by logistic regression controlling for age and adjusting for multiple comparisons (FDR method). Two tag-SNPs, rs11249969 and rs81442 (with a pairwise r2 value of 0.41), were associated with the global EDI-2 score, which measures EDI-related psychopathology (adjusted FDR-q = 0.02 and 0.04, respectively). Moreover, rs81442 significantly modulated all the scales of the SCL-90R test that evaluates general psychopathology (FDR-q values ranged from 4.1E-04 to 0.011). A sliding-window analysis using adjacent 3-SNP haplotypes revealed a proximal region of the MSRA gene spanning 187.8 Kbp whose variability deeply affected psychopathological symptoms of the AN patients. Depression was the symptom that showed the strongest association with any of the constructed haplotypes (FDR-q = 3.60E-06). No variants were found to be linked to AN risk or anthropometric parameters in patients or controls. Variability in the MSRA gene locus modulates psychopathology often presented by AN patients.

Genetic Interactions with Intrauterine Diabetes Exposure in Relation to Obesity: The EPOCH and Project Viva Studies

To examine whether BMI-associated genetic risk variants modify the association of intrauterine diabetes exposure with childhood BMI z-scores, we assessed the interaction between 95 BMI-associated genetic variants and in utero exposure to maternal diabetes among 459 children in the Exploring Perinatal Outcomes among Children historical prospective cohort study (n = 86 exposed; 373 unexposed) in relation to age- and sex-standardized childhood BMI z-scores (mean age = 10.3 years, standard deviation = 1.5 years). For the genetic variants showing a nominally significant interaction, we assessed the relationship in an additional 621 children in Project Viva, which is an independent longitudinal cohort study, and used meta-analysis to combine the results for the two studies. Seven of the ninety-five genetic variants tested exhibited a nominally significant interaction with in utero exposure to maternal diabetes in relation to the offspring BMI z-score in EPOCH. Five of the seven variants exhibited a consistent direction of interaction effect across both EPOCH and Project Viva. While none achieved statistical significance in the meta-analysis after accounting for multiple testing, three variants exhibited a nominally significant interaction with in utero exposure to maternal diabetes in relation to offspring BMI z-score: rs10733682 near LMX1B (interaction β = 0.39; standard error (SE) = 0.17), rs17001654 near SCARB2 (β = 0.53; SE = 0.22), and rs16951275 near MAP2K5 (β = 0.37; SE = 0.17). BMI-associated genetic variants may enhance the association between exposure to in utero diabetes and higher childhood BMI, but larger studies of in utero exposures are necessary to confirm the observed nominally significant relationships.

Association between rs1421085 and rs9939609 Polymorphisms of Fat Mass and Obesity-Associated Gene with High-Density Lipoprotein Cholesterol and Triglyceride in Obese Turkish Children and Adolescents

Several studies have shown that rs9939609 and rs1421085 in fat mass and obesity-associated ( FTO ) gene rs17782313 and rs12970134 in melanocortin-4 receptor ( MC4R ) gene influence obesity. In the present study, we aimed to determine association between rs9939609, rs1421085, rs17782313, and rs12970134 polymorphism, and their relation with body mass index (BMI), glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and lipid values in obese children. We included 100 newly diagnosed obese children and 100 healthy children. The rs1421085 (CC/CT) ( p  = 0.019) and rs9939609 (AA/AT) ( p  = 0.002) polymorphism regions were higher in the obese group. Additionally, we found that both the rs1421085 (CC/CT) and rs9939609 (AA/AT) polymorphism associated with high-density lipoprotein cholesterol ( p  = 0.011 and p  = 0.003) and triglycerides ( p  = 0.01 and p  = 0.004) level, respectively. Further, the rs9939609 and rs1421085 variants of FTO gene associated with HDL-cholesterol and triglycerides levels in obese children; however, updated studies with a large sample size are required to establish strong links with genetic variants and risk factors in childhood obesity.

Association of UCP1, UCP2 and UCP3 gene polymorphisms with cardiovascular disease risk factors in European adolescents: the HELENA study

BACKGROUND

Cardiovascular diseases (CVDs) are responsible for 31% of all deaths worldwide. Genetic predisposition to CVDs in adolescents remains largely unknown. The aim of this study was to examine the association of UCP1, UCP2 and UCP3 gene polymorphisms with CVD risk factors in European adolescents.

METHOD

A cross-sectional study that involves 1.057 European adolescents (12-18 years old) from the HELENA study. A total of 18 polymorphisms of UCP1, UCP2 and UCP3 genes were genotyped. We measured serum total cholesterol, high-density lipoprotein,low-density lipoprotein, ApoA1, ApoB, leptin, triglycerides, glucose, insulin and blood pressure, and calculated HOMA (homeostatic model assessment), Quantitative Insulin Sensitivity Check Index (QUICKI) and a CVD risk score.

RESULTS

The G allele of UCP2 rs2735572 and T allele of UCP2 rs17132534 were associated with higher diastolic blood pressure (P = 0.001; false discovery rate [FDR] = 0.009 and P = 8e-04; FDR = 0.009, respectively). We observed that the AATAG haplotype of UCP1 was associated with higher serum ApoB/ApoA1 (P = 0.008; FDR = 0.031) and ApoB levels (P = 0.008; FDR = 0.031). Moreover, the ACC haplotype of UCP3 was associated with a higher CVD risk score (P = 0.0036; FDR = 0.01).

CONCLUSIONS

Two UCP2 polymorphisms and haplotypes of UCP1 and UCP3 were associated with CVD risk factors. These findings suggest that UCPs may have a role in the development of CVD already in adolescents.

Analysis of Polymorphisms rs7093069-IL-2RA, rs7138803-FAIM2, and rs1748033-PADI4 in the Group of Adolescents With Autoimmune Thyroid Diseases

INTRODUCTION

The pathogenesis of autoimmune thyroid diseases is complicated and not completely known. Among the causes of thyroid autoimmunity, we distinguish genetic predisposition and environmental factors. Graves' disease and Hashimoto's thyroiditis are associated with a disturbance of immune tolerance of thyroid antigen molecules. The IL2RA gene is located on chromosome 10 and encodes the interleukin 2 receptor (IL2RA), which is expressed by the regulatory T-cells (Tregs) responsible for suppression. It has been shown that this gene and its polymorphism occur in people with various autoimmune diseases (e.g. type 1 diabetes mellitus, rheumatoid arthritis, Graves' disease, or multiple sclerosis). The FAIM2 gene is located on chromosome 12 and encodes the molecule involved in the apoptosis inhibition process. The PADI4 gene is located on chromosome 1, and its expression is associated with activation of T-cells, differentiation of macrophages, which leads to increased inflammation.

AIM

The aim of the study was to analyze the polymorphisms of the IL-2RA (rs7093069), FAIM2 (rs7138803) and PADI4 (rs1748033) genes and their correlation to thyroid hormones and anti-thyroid antibodies in pediatric patients with Graves' disease and Hashimoto's thyroiditis compared to the control group.

MATERIAL AND METHODS

The study was performed in 180 patients with GD (mean age 16.5 ± 2), 80 with HT (mean age, 15.2 ± 2.2), and 114 children without any autoimmune diseases (mean age 16.3 ± 3) recruited from the endocrinology outpatient clinic. Three single nucleotide polymorphisms (SNPs): rs7138803-FAIM2, rs7093069-IL-2RA, and rs1748033 PADI4 were determined by TaqMan SNP QuanStudio 12K Flex-OpenArray genotyping with PCR and correlated to thyroid hormones and anti-thyroid antibodies.

RESULTS

Rs7090369-IL-2RA allele T was more frequent in patients with AITDs (33.7% in GD vs 28.7% in HT, p = 0.077, OR = 1.52) compared with healthy children (25%). Allele T of that gene predisposes to the occurrence of autoimmune thyroid diseases, especially GD and TT genotype gives a statistically significant 5.2 times higher risk of GD (p = 0.03, OR = 5.26) and increased risk of HT (p = 0.109, OR = 4.46). Allele A rs7138803-FAIM2 is more frequent in patients with GD (p = 0.071, OR = 1.45) and HT (p = 0.028, OR = 1.8). In our data the presence of GG genotype of that gene significantly reduces the risk of autoimmune thyroid diseases (p = 0.05, OR = 0.42). Allele C rs1748033PADI4 and its CC genotype were more frequent in patients with autoimmune thyroid diseases, but it was not statistically significant. The occurrence of CT genotype significantly reduces the risk of HT (p = 0.03, OR = 0.4).

CONCLUSIONS

1). Polymorphisms rs7138803-FAIM2 and rs1748033-PADI4 are more frequent in patients with autoimmune thyroid diseases, more frequent in patients with Hashimoto' thyroiditis, but the occurrence of GG rs7138803-FAIM2 genotype could reduce the risk of thyrocyte apoptosis inhibition. 2). The TT rs7093069-IL2RA genotype may increase the risk of autoimmune thyroid diseases. 3). Analysis of polymorphisms of given genes in clinical practice will allow to determine predisposition to autoimmune thyroid disease development, to find symptoms of thyroid gland dysfunction earlier and to use appropriate treatment.

Effects of Breastfeeding and Formula Feeding on the Expression Level of FTO, CPT1A and PPAR-α Genes in Healthy Infants

PURPOSE

The study aimed to investigate the effect of breastfeeding, formula feeding and mix feeding (breastfed plus formula-fed) on the expression level of obesity-predisposing genes including fat mass and obesity-associated (FTO), carnitine palmitoyltransferase 1A (CPT1A), and peroxisome proliferator-activated receptor-α (PPAR-α) in 5- to 6-month-old infants.

PATIENTS AND METHODS

A total of 150 infants participated in this case-control study. All subjects were healthy infants aged 5-6 months that divided into 3 groups: breastfed, formula-fed, and mix-fed. The expression level of FTO, CPT1A, and PPAR-α genes in peripheral blood mononuclear cells (PBMC) was evaluated in each group using reverse transcription-polymerase chain reaction (RT-PCR) method.

RESULTS

Our findings showed that the current weight, height, and head circumference of infants in the formula feeding and mix feeding groups were significantly higher than those in the exclusive breastfeeding group. The expression level of FTO and CPT1A genes in formula-fed and mix-fed infants was significantly higher (p<0.001) than that in breastfed infants, while the expression level of PPAR-α gene was significantly lower (p<0.05).

CONCLUSION

Breastfeeding showed modulatory effects on the expression level of obesity-predisposing genes and can protect against obesity and subsequent non-communicable diseases. However, more investigations are required to explain the epigenetic effects of breast milk.

The FTO Gene and Measured Food Intake in 5- to 10-Year-Old Children Without Obesity

OBJECTIVE

Genetic variation in the first intron of FTO (e.g., single-nucleotide polymorphism [SNP] rs9939609) is strongly associated with adiposity. This effect is thought to be mediated (at least in part) via increasing caloric intake, although the precise molecular genetic mechanisms are not fully understood. Prior pediatric studies of FTO have included youth with overweight and obesity; however, they have not informed whether a genotypic effect on ingestive behavior is present prior to obesity onset. Therefore, this study investigated the association between FTO and caloric intake in children aged 5 to 10 years without obesity (adiposity ≤ 95th percentile).

METHODS

A total of 122 children were genotyped for rs9939609 and ate ad libitum from a laboratory lunch buffet following a standardized breakfast. Linear regressions, adjusting for body mass, were used to examine the association between FTO "dose" (number of copies of SNP rs9939609) and intake variables.

RESULTS

There was a significant association between FTO and total intake. Each risk allele predicted an additional 64 calories, accounting for 3% of the variance. There were no associations between FTO and macronutrient preference, energy density, or diet variety. Results were influenced by race.

CONCLUSIONS

Results corroborate and extend prior work by showing a dose-dependent effect on food intake in children without obesity.

Association between UCP1, UCP2, and UCP3 gene polymorphisms with markers of adiposity in European adolescents: The HELENA study

AIMS

To examine the association between UCP1, UCP2, and UCP3 gene polymorphisms with adiposity markers in European adolescents and to test if there were gene interactions with objectively measured physical activity and adiposity.

METHODS

A cross-sectional study that involves 1.057 European adolescents (12-18 years old) from the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study. A total of 18 polymorphisms in UCP1, UCP2, and UCP3 genes were genotyped. We measured weight, height, waist, and hip circumferences and triceps and subscapular skinfold thickness. Physical activity was objectively measured by accelerometry during 7 days.

RESULTS

The C allele of the UCP1 rs6536991 polymorphism was associated with a lower risk of overweight (odds ratio [OR]: T/C + C/C vs T/T) = 0.72; 95% confidence interval [CI]: 0.53-0.98; P = 0.034; false discovery rate [FDR] = 0.048). There was a significant interaction between UCP1 rs2071415 polymorphism and physical activity with waist-to-hip ratio (P = 0.006; FDR = 0.026). Adolescents who did not meet the physical activity recommendations (less than 60 min/day of moderate to vigorous physical activity) and carrying the C/C genotype had higher waist-to-hip ratio (+ 0.067; 95% CI, 0.028-0.106; P = 0.003), while no differences across genotypes were observed in adolescents meeting the recommendations.

CONCLUSIONS

Two UCP1 polymorphisms were associated with adiposity in European adolescents. Meeting the daily physical activity recommendations may overcome the effect of the UCP1 rs2071415 polymorphism on obesity-related traits.

Genetic risk score based on fat mass and obesity-associated, transmembrane protein 18 and fibronectin type III domain containing 5 polymorphisms is associated with anthropometric characteristics in South Brazilian children and adolescents

The prevalence of childhood obesity has increased worldwide. Although it is considered a polygenic inheritance disease, little is known about its susceptibility when the additive effect is considered. The aim of this study is to investigate whether the genetic risk score (GRS) based on previously associated obesity polymorphisms (SNP) rs9939609 (fat mass and obesity-associated (FTO)), rs6548238 (transmembrane protein 18 (TMEM18)) and rs16835198 (fibronectin type III domain containing 5 (FNDC5)) could serve as a predictor for anthropometric characteristics in a sample of Brazilian children and adolescents. This is a cross-sectional study with 1471 children and adolescents aged 6–17 years. BMI, waist circumference (WC) and percentage of body fat and metabolic parameters were verified. In all, three SNP were genotyped by TaqMan™ allelic discrimination. The metabolic and anthropometric parameters were compared between the genotypes, and the unweighted and weighted GRS (GRS and wGRS, respectively) were created to test the additive effect of these genetic polymorphisms on anthropometric parameters. The prevalence of overweight plus obesity was 41 %. Significant associations were identified forFTOrs9939609,TMEM18rs6548238 andFNDC5rs16835198 and for GRS and wGRS with anthropometric phenotypes. The higher score of wGRS was associated with obesity (OR: 2·65, 95 % CI 1·40, 5·04,P=0·003) and with greater WC (OR: 2·91, 95 % CI 1·57, 5·40,P=0·001). Our results suggest that these genetic variants contribute to obesity susceptibility in children and adolescents and reinforce the idea that the additive effect may be useful to elucidate the genetic component of obesity.