The obesity epidemic has been largely attributed to changes in lifestyle habits established over the past three decades. These changes are mainly attributed to excessive nutrition and decline in physical activity as well as additional factors such as reduced intestinal microbiota diversity, sleep duration, endocrine disruptors, and reduced variability of the ambient temperature. However, the obesogenic environment is not sufficient to determine the presence of obesity, it is necessary that the lifestyle becomes associated with a personal predisposition for the phenotype to emerge. In this article, we review the main forms of monogenic and syndromic obesity, as well as a historical summary of the search for the genes that add up to confer greater risk for the development of polygenic obesity. Methods We carried out a PubMed search, along with ExcerptaMedica database (EMBASE)/Cochrane library, Web Sciences for the Medical Subject Headings (MeSH) terms "obesity'' AND "genetics" for the past 5-years. Results We found a total of 14057 articles pertaining to obesity and genetics together of which we selected 92 articles for this review after getting articles after searching cross references. Conclusion Studies with twins and adopted children show that 55 to 80% of the variation of body mass index (BMI) is attributed to genetic factors. According to the genetic criteria, obesity can be classified as A) Monogenic-when a mutated gene is responsible for the phenotype; B) Syndromic-when a set of specific symptoms are present and a small group of genes is involved; usually the term is used to describe obese patients with cognitive delay, dysmorphic features, organ-specific abnormalities, hyperphagia, and/or other signs of hypothalamic dysfunction; C) Polygenic-also called "common" obesity, present in up to 95% of cases. Many genes add up to give a greater risk to the individual, and if associated with some habits culminates in obesity. In spite of its great relevance, the search for the genes that raise the risk of obesity has not been easy. It is still a challenge for the scientific community to separate the genetic element from the environmental component in the etiology of this disease. Individuals more susceptible to excessive adiposity may carry risk variants in the genes that influence appetite control, the regulation of cellular machinery, lipid metabolism and adipogenesis, the energy expenditure, insulin signaling, and inflammation.

Regulation of food intake, energy expenditure and store are strikingly linked to obesity. Homeostatic control of food intake, hunger and satiety involves adipose and gastrointestinal hormones, such as leptin, insulin and ghrelin, which eventually affect neuronal signaling in the hypothalamus arcuate nucleus. On the other hand, hedonic control of food intake relates to substances such as opioids, endocannabinoids, gamma-aminobutyric acid, serotonin and dopamine, which act on the motivation and reward mechanisms. Dopamine is a precursor of noradrenaline and adrenaline and modulates a number of physiological functions, such as appetite, depending on the brain area and the type of receptor stimulated. It has been established as the main neurotransmitter of the hypothalamic reward system. Beyond the homeostatic and hedonic energy balance control, genetic aspects are also tightly involved in obesity pathophysiology. In this context, some Single Nucleotide Polymorphism (SNP) has been linked to common obesity. Here, we highlight the role of the dopamine receptor D2 gene TaqAI polymorphism, which affects the D2 receptor availability and has been associated to obesity. Therefore, the aim of this mini review is to cover basic aspects of food intake, energy balance, dopamine-related aspects, including genetic ones, and the relation with obesity.

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A estabilidade do número e da morfologia dos cromossomos em qualquer organismos é fundamental para o seu desenvolvimento harmonioso. Alterações numéricas são correspondentes a perda ou ao acréscimo de cromossomos no cariótipo, sendo classificadas como explodias e aneuploidias. A trissomia do cromossomo X é uma aneuploidia, relacionada com a não disjunção durante o período meiótico, ocorrendo de 1 em 1000 nativivos. Neste caso, as células apresentam dois cromossomos X inativos durante a intérfase, apresentando dois corpúsculos de Barr. Sendo esta, a anormalidade cromossômica feminina mais comum, porém não resultante em uma síndrome especifica. A monossomia ocorre quando um dos cromossomos do par não está presente, formando uma constituição com 45 cromossomos. Sendo esta anormalidade relacionada com a Síndrome de Turner. A não disjunção e a perda cromossômica durante a anáfase, são mecanismos patogênicos que levam a monossomia do cromossomo X. O objetivo deste trabalho foi relatar um caso de uma paciente com indicação clinica para a Síndrome de Turner e caso de mosaicismo. A paciente, do sexo feminino, foi encaminhada pelo médico assistente ao LaGene (Laboratório de Citogenética Humana e Genética Molecular) em parceria com o Núcleo de Pesquisas Replicon, com indicação de síndrome de Turner e mosaicismo cromossômico para a realização do cariótipo. Após a assinatura do Termo de Consentimento Livre e Esclarecido, o cariótipo foi realizado mediante cultura de Linfócitos T a curto prazo (48 horas), bandeamento GTG com 550 bandas e análise das metáfases usando o software IKAROS® (Metasystem, German), sendo analisados um total de 30 células. O resultado da citogenética convencional apresentou um cariótipo de mosaico com 66% das células analisadas com trissomia do X (47,XXX) e 34 % com monossomia do X (45,X). Em geral, não se pode prever um fenótipo resultante nessas condições de Mosaicismo.

Citation ResearchPage 64 ABSTRACT Background: Reward Deficiency Syndrome (RDS) is a hypo-dopaminergic state that predisposes to obsessive-compulsive behaviors. Obesity is part of RDS since the individual is predisposed to reward-driven eating behavior that leads to overeating. The allele A1 of the SNP C32806T in Dopamine D2 receptor gene (DRD2) is associated with reduction of DRD2 levels and higher BMI in adults. DRD2 are expressed in beta cells and modulate insulin secretion. The aim of this study is to investigate the relation between this SNP and obesity and metabolic alterations in children. Methods: Fifty five obese children and 50 healthy controls were analyzed for DRD2 Taq1A polymorphism Genotyping was performed by polymerase chain reaction and restriction fragment length polymorphism. Glucose, insulin and lipid profile were measured. The Homeostatic model assessment (HOMA) was calculated. Results: We found three genotypes: A1A1(12,4%), A1A2(33,3%) and A2A2(54,3%). The A1 allele was more present in: obese than in euthrophic (34,5%*23%), in children with altered HOMA ß (38,2% * 24,6%), children with altered Total Cholesterol (35,2%*19,5%) and lower levels of triglycerides. Children were divided in 4 subgroups in accordance to the function of pancreatic beta cells and BMI-Z; subgroups with normal secreting pancreatic beta cell demonstrated significant difference for allelic and genotypic distribution, with lower presence of A1A1 and A1A2 genotypes and higher presence of A2 allele. Conclusions: Besides confirming the association with childhood obesity, our results show for the first time that: A1 allele is associated with TC≥170 mg/dl, lower TG levels and HOMA ß ≥175. A2 allele is associated with normal HOMA ß, being a protective factor for pancreatic secretion. The recognition of predisposed individuals through determinations of risks polymorphisms can lead to new paths for treatment and prevention of metabolic abnormalities.

RESUMO Objetivo: nosso objetivo é descrever a distribuição epidemiológica das internações e óbitos pós-operatórios, bem como as tendências das cirurgias bariátricas realizadas pelo SUS em todas as unidades federativas (UFs) brasileiras a partir de uma análise do período de 2009 a 2019. Métodos: trata-se de um estudo observacional descritivo ecológico de série temporal com análise quantitativa e descritiva, com base em dados secundários. O período analisado foi de 2009 a 2019. Coletamos, no DATASUS, dados de homens e mulheres que possuem obesidade e foram internados após terem sido submetidos à cirurgia bariátrica. A regressão de Prais-Winsten foi utilizada para identificar as tendências. Resultados: no período, 83.829 cirurgias bariátricas foram realizadas, tendo 161 evoluído para óbitos, o que representa 0,19% dos procedimentos. Encontramos uma tendência crescente no número de cirurgias para o Brasil (β=0,04; p<0,001), mas 11 UFs apresentaram tendência estacionária e três, decrescente (seis UFs não tinham dados suficientes para entrar na análise). Nas regiões Norte e Nordeste prevaleceram tendências estacionárias, enquanto no Centro-Oeste, as decrescentes, e no Sul e Sudeste, as crescentes. Conclusões: encontramos uma evidente disparidade entre as regiões, sugerindo deficiências de acesso à saúde. Ao demonstrar quais UFs e características demográficas apresentam menores índices de cirurgias, nosso estudo é capaz de direcionar políticas públicas para uma saúde pública brasileira mais igualitária.

Objective: our objective is to describe the epidemiological distribution of hospitalizations and postoperative deaths, as well as the trends of bariatric surgeries performed by SUS in all Brazilian federative units (FUs) from an analysis of the period from 2009 to 2019. Methods: This is an observational, descriptive ecological time-series study with quantitative and descriptive analysis, based on secondary data. The period analyzed was from 2009 to 2019. We collected, from DATASUS, data from obese men and women who were hospitalized after undergoing bariatric surgery. Prais-Winsten regression was performed to identify the trends. Results: In the period, 83,829 bariatric surgeries were performed, of which 161 resulted in death, representing 0.19% of the procedures. We found an increasing trend in the number of surgeries for Brazil (β=0.04; p<0.001), but 11 FUs showed a stationary trend and three, decreasing ones (six UFs did not have enough data to enter the analysis). In the North and Northeast regions, stationary trends prevailed, while in the Center-West, the decreasing trends, and in the South and Southeast, the increasing ones. Conclusions: we found an evident disparity between regions, suggesting deficiencies in access to health. By demonstrating which FUs and demographic characteristics have the lowest rates of surgeries, our study is able to direct public policies towards a more egalitarian Brazilian public health.