Search

OBJECTIVES To investigate whether objectively measured physical activity (PA) modulates the association between the FTO rs9939609 polymorphism and obesity variables in a sample of Portuguese children. METHODS A total of 440 children (213 girls and 227 boys) aged 3 to 11 years were observed. Genotyping was performed using TaqMan assay. Body mass index (BMI), BMI Z scores, waist circumference (WC), and waist-to-height ratio (WHtR) were calculated. PA was estimated in 399 children by accelerometry. RESULTS Linear regression, in the additive model, showed that the rs9939609 minor A-allele significantly associated with BMI (P = .029), BMI Z score (P = .017), WC (P = .016), and WHtR (P = .019). Logistic regression, in the additive model, showed a marginally significant association between the A-allele and overweight/obesity (odds ratio [OR]: 1.372; P = .049). When stratified by sex, rs9939609 showed marginal or significant associations with BMI (P = .08), BMI Z score (P = .07), WC (P = .005), WHtR (P = .02), and overweight/obesity (OR: 1.529; P = .064) in girls but not in boys (P > .05). Significant interactions were not found between the FTO polymorphism and PA (inactive vs active groups of children) for BMI (P = .461), BMI Z score (P = .387), WC (P = .757), or WHtR (P = .621). CONCLUSIONS Findings of the present study highlight the association between FTO rs9939609 and obesity or body fat indices in girls but not in boys. PA was not found to mediate the impact of FTO genetic variation on risk of obesity.

Summary We screened for mutations in the MC4R and LEPR genes and investigated the genotype-phenotype correlation in obese individuals belonging to families with evident hereditary patterns of severe and early-onset obesity among the Iberian population. A total of 202 unrelated and severely obese patients since childhood, were enrolled in the study. Bidirectional sequencing of the MC4R gene was carried out in all patients; the LEPR gene was sequenced in 15 individuals based on additional clinical signals. Segregation analysis and/or genotype-phenotype description was performed for subjects with the new mutations and with presumably functional variants. Ten MC4R gene mutations were identified in the heterozygous state in 10 patients. Mutations p.R147G and p.G323E are new and mutations p.R7H, p.G32E, p.H76R, p.V103I, p.S127L, p.T150I, p.I251L and p.G252S were previously described. A new dinucleotide insertion -77_-76insTA in the promoter region of the LEPR gene was found in the heterozygous state in one patient. The new p.R147G and the previously published p.R7H, p.S127L, p.T150I and p.G252S MC4R mutations, cosegregate with obesity in our patients and were predicted to be deleterious. For the novel MC4R p.G323E and LEPR -77_-76insTA gene mutations, the genotype-phenotype correlation and bioinformatic analysis did not clarify whether these mutations are indeed implicated in obesity.

Aim The -13910C>T single nucleotide polymorphism located upstream of the lactase gene (LCT) was found tightly associated with lactase persistence in European populations. Recently, it was also associated with body mass index (BMI) and obesity in European adults. The aim of this study was to test the association of -13910C>T polymorphism with obesity-related traits and risk of obesity in children. Methods We genotyped 580 Portuguese children (6–12-year-olds) for the -13910C>T polymorphism using TaqMan probes by real-time PCR. Anthropometric measurements were assessed in all children. Obesity was defined according to the International Obesity Task Force (IOTF) cut-offs and abdominal obesity using the sex and age-specific ≥90th waist circumference percentile. Results We found indication for an association between the-13910*T allele and children abdominal obesity (odds ratio [OR] = 1.41; 95% confidence intervals [CI]: 1.03–1.94; p = 0.030). Under the dominant model, the indicative association was observed between the LCT-13910 CT/TT genotypes and abdominal obesity, remaining significant after adjustment for age and gender (OR = 1.65; 95% CI: 1.04–2.60; p = 0.029). No association was detected with the risk of obesity (p = 0.350). Conclusion Our results suggest that the -13910C>T polymorphism may predispose to abdominal obesity in Portuguese children. The association with BMI or risk of obesity, previously observed in adults, was not confirmed.

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