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Ana Carolina Proença da Fonseca,1,2 Gabriella de Medeiros Abreu,2 Lohanna Palhinha,1 Verônica Marques Zembrzuski,2 Mario Campos Junior,2 João Regis Ivar Carneiro,3 José Firmino Nogueira Neto,4 Fernanda Cristina C Mattos Magno,5 Eliane Lopes Rosado,5 Clarissa Menezes Maya-Monteiro,1 Giselda Maria Kalil de Cabello,2 Pedro Hernán Cabello,2,6 Patricia Torres Bozza1 1Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil; 2Human Genetics Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil; 3Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 4Department of Pathology and Laboratory, Rio de Janeiro State University, Rio de Janeiro, Brazil; 5Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 6Human Genetics Laboratory, Grande Rio University, Rio de Janeiro, BrazilCorrespondence: Ana Carolina Proença da FonsecaHuman Genetics Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, 4365 Brasil Avenue, Leônidas Deane Building – Office 611/615, Rio de Janeiro, RJ 21040-360, BrazilTel +552138658192Fax +552138658239Email ana.proenca@ioc.fiocruz.brBackground: Brain-derived neurotrophic factor (BDNF) is a pro-survival factor in the brain that also regulates energy balance. BDNF loss-of-function point mutations are responsible for haploinsufficiency, causing severe early-onset obesity. Up to date, only a few studies have sequenced this gene to search for rare mutations related to obesity. In this study, we aimed to investigate the prevalence of BDNF variants in a cohort of adults with severe obesity from Brazil.Material and Methods: This study comprised 201 adults with severe obesity (BMI ≥ 35.0 kg/m2) with onset during childhood- or adolescence/youth. As controls, 73 subjects with normal weight (18.5 ≤ BMI ≤ 24.9 kg/m2) were selected. The exclusion criteria were pregnancy, lactation, the use of medication to lose or gain weight, and the presence of symptoms suggestive of syndromic obesity (only for the case group). The coding region of the BDNF gene was screened by Sanger sequencing. Demographic, anthropometric, and blood pressure parameters were obtained from the participants as well as serum hormone and cytokines concentrations and biochemical values.Results: As a result, three missense variants [p.(Thr2Ile), p.(Val66Met), and p.(Arg209Gln)] and four synonymous variants (p.Leu107=, p.Thr149=, p.Ala150=, and p.Ser213=) were identified. The p.(Arg209Gln) was predicted as pathogenic by all in silico algorithms used and was not observed in the control group. The individuals carrying the p.(Val66Met) mutated allele had higher waist circumference, HDL-cholesterol and MCP1 levels, and reduced risk of developing metabolic syndrome.Conclusion: We observed that the common BDNF p.(Val66Met) variant has influenced waist circumference, HDL-cholesterol, and MCP1 levels. This polymorphism has also a protective effect on metabolic syndrome susceptibility. Additionally, we described for the first time a rare potentially pathogenic BDNF variant in a Brazilian patient with severe obesity and childhood-onset.Keywords: BDNF, severe obesity, rare mutation, early-onset obesity, metabolic syndrome

Ana Carolina Proença da Fonseca,1 Gabriella Medeiros Abreu,1 Verônica Marques Zembrzuski,1 Mario Campos Junior,1 João Regis Ivar Carneiro,2 José Firmino Nogueira Neto,3 Giselda Maria Kalil Cabello,1 Pedro Hernán Cabello1,41Human Genetics Laboratory, Oswaldo Cruz Institute/FIOCRUZ, Rio de Janeiro, Brazil; 2Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 3Department of Pathology and Laboratory, Rio de Janeiro State University, Rio de Janeiro, Brazil; 4Human Genetics Laboratory, Grande Rio University, Rio de Janeiro, BrazilBackground: Obesity occurs due to the interaction between the genetic background and environmental factors, including an increased food intake and a sedentary lifestyle. Nowadays, it is clear that there is a specific circuit, called leptin-melanocortin pathway, which stimulates and suppresses food intake and energy expenditure. Therefore, the aim of this study was to evaluate the influence of genetic variants related to appetite regulation and energy expenditure on severe obesity susceptibility and metabolic phenotypes in a Brazilian cohort.Material and methods: A total of 490 participants were selected (298 severely obese subjects and 192 normal-weight individuals). Genomic DNA was extracted and polymorphisms in protein related to agouti (AGRP; rs5030980), ghrelin (GHRL; rs696217), neuropeptide Y (NPY; rs535870237), melanocortin 4 receptor (MC4R; rs17782313), brain-derived neurotrophic factor (BDNF; rs4074134) and fat mass and obesity-associated (FTO; rs9939609) genes were genotyped using TaqMan® probes. Demographic, anthropometric, biochemical and blood pressure parameters were obtained from the participants.Results: Our results showed that FTO rs9939609 was associated with severe obesity susceptibility. This polymorphism was also related to body weight, body mass index (BMI), waist to weight ratio (WWR) and inverted BMI. Individuals carrying the mutant allele (A) showed higher levels of BMI as well as lower values of WWR and inverted BMI.Conclusion: This study showed that FTO rs9939609 polymorphism plays a significant role in predisposing severe obesity in a Brazilian population.Keywords: leptin-melanocortin pathway, FTO, obesity, polymorphisms, hypothalamus

Ana Carolina Proença da Fonseca,1 Gabriella de Medeiros Abreu,1 Verônica Marques Zembrzuski,1 Mario Campos Junior,1 João Regis Ivar Carneiro,2 Fernanda Cristina C Mattos Magno,3 Eliane Lopes Rosado,3 José Firmino Nogueira Neto,4 Giselda Maria Kalil de Cabello,1 Pedro Hernán Cabello1,5 1Human Genetics Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil; 2Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 3Institute of Nutrition Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 4Department of Pathology and Laboratory, Rio de Janeiro State University, Rio de Janeiro, Brazil; 5Human Genetics Laboratory, Grande Rio University, Rio de Janeiro, Brazil Background: Melanocortin 4 receptor gene (MC4R) is an important regulator of food intake, body weight, and blood pressure. Mutations in MC4R are associated with the most common form of nonsyndromic monogenic obesity. MC4R variations have an autosomal co-/dominant model of inheritance. MC4R screening could reveal individuals previously unrecognized with Mendelian form of obesity for further clinical management and genetic counseling. However, there are limited data regarding MC4R variants in patients with obesity from Brazil. The aim of this study was to screen the coding region of the MC4R gene in a Brazilian cohort of severely obese adults and to investigate the phenotype–genotype correlation within MC4R variant carriers. Methods: This study comprised 157 adult participants, stratified according to the period of obesity onset. The first group included 97 patients with childhood-onset obesity (0–11 years) and the second group comprised 60 subjects with adolescence/youth-onset obesity (12–21 years). The entire coding region of MC4R gene was screened by Sanger sequencing. Results: As a result, five previously described variants (Met1?, Ser36Thr, Val103Ile, Ile98=, and Phe202Leu) were identified. Met1? is a start lost codon variant, which affects the translation of MC4R. It was found in a female patient with childhood-onset obesity. We also compared the anthropometric and metabolic parameters between patients with MC4R missense variants (Ser36Thr, Val103Ile, and Phe202Leu) and noncarriers. Patients carrying MC4R variants had higher median of waist–hip ratio when compared to noncarriers (P=0.048). These missense variants were also associated with hypertension (P=0.014). Additionally, Val103Ile carriers had lower diastolic blood pressure and lower systolic blood pressure compared to noncarriers (P=0.020 and P=0.065, respectively). Val103Ile was also associated with hypertension (P=0.003). Conclusion: This study showed the prevalence of MC4R variants in a cohort of Brazilian adults with severe obesity. We also identified significant phenotype differences between carriers and noncarriers of missense variants in our sample, suggesting an important role of MC4R on body fat distribution and blood pressure. Keywords: MC4R, severe obesity, mutation, start lost, blood pressure

Fernanda Cristina Carvalho Mattos Magno,1 Helena Chrispim Guaraná,1 Ana Carolina Proença Fonseca,2 Giselda Maria Kalil Cabello,2 João Régis Ivar Carneiro,3 Aline Pereira Pedrosa,1 Ana Carolina Ximenes,1 Eliane Lopes Rosado1 1Institute of Nutrition, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil; 2Oswaldo Cruz Foundation (FIOCRUZ), Oswaldo Cruz Institute (IOC), Human Genetics Laboratory, Rio de Janeiro, RJ, Brazil; 3Federal University of Rio de Janeiro, University Hospital Clementino Fraga Filho, Service of Nutrology, Rio de Janeiro, RJ, Brazil Background: The fat mass and obesity-related (FTO) gene has a strong relationship with obesity, extreme obesity and inflammatory state, and may also be associated with food intake regulation.Objective: The aim of the present study was to evaluate the influence of the rs9939609 single-nucleotide polymorphism of the FTO gene on appetite, ghrelin, leptin, interleukin 6 (IL6), tumor necrosis factor α (TNFα) levels and food intake of morbidly obese women.Materials and methods: The study comprised 70 women, aged between 20 and 48 years, from Rio de Janeiro, Brazil. The participants were selected according to the body mass index between 40 and 60 kg/m2. Anthropometric and biochemical data were measured during fasting. Hormones and inflammatory data were measured before and after the participants ate an isocaloric meal. Dietary records were calculated and analyzed using a nutritional assessment program. Visual analog scales were used for behaviors of the sensations of appetite and food preferences. The FTO rs9939609 variant was genotyped using real-time polymerase chain reaction.Results: Participants with the AA genotype had lower values of ghrelin and IL6 and higher values of leptin than those with TT and TA in the postprandial period. Comparing the plasma concentrations of ghrelin, insulin, IL6 and TNFα intragenotypes, it was observed that those with TT had decreased leptin and increased IL6 at the postprandial period. Subjects with TA showed increased postprandial IL6, and those with AA had decreased postprandial ghrelin. There was no difference in TNFα intra- and intergenotypes. The postprandial sensations of hunger were lower in AA than those with TT. There were differences between genotypes regarding ingested grams of protein by weight, cholesterol, B3, B5, B6 and B12 vitamins, and selenium potassium and sodium minerals.Conclusion: These findings suggest that genetics may exert an influence on physiologic factors and might alter eating behavior. Keywords: obesity, rs9939609, hormones, inflammatory cytokines, food intake, binge eating