A Rare Potential Pathogenic Variant in the BDNF Gene is Found in a Brazilian Patient with Severe Childhood-Onset Obesity.

BACKGROUND: 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.

Obesidad monogénica / Monogenic obesity

La obesidad infantil es un problema creciente de salud, asociado con una significativa morbilidad física y psicológica a edades tempranas. La obesidad es una enfermedad multifactorial, causada en la mayoría de los casos por la interacción de determinados polimorfismos genéticos con el medio ambiente. Solo en un 5 % resulta de mutaciones en genes específicos, originando en algunos casos síndromes mendelianos de muy escasa incidencia en la población que se clasifican como obesidades monogenicas. La mayoría de estos genes están implicados en la regulación del hambre-saciedad en el sistema nervioso central, en el cual el eje de leptina-melanocortina desempeña un rol fundamental. Se presentan clínicamente como formas de obesidad de inicio precoz, severas, que se asocian con trastornos de la conducta alimentaria y alteraciones endocrinológicas. La mutación en el gen del receptor melanocortina-4 (MC4R) es la causa más común de obesidad monogénica grave de aparición temprana. El objetivo de esta revisión es realizar una actualización sobre las obesidades de inicio precoz de causa monogénicas, su etiopatogenia, sus principales características clínicas y su abordaje terapéutico. El manejo de estos pacientes aún es un reto, ya que el tratamiento específico solo se encuentra disponible en un solo tipo de obesidad monogénica. Para el resto de los tipos se encuentran en investigación nuevas moléculas que actúan sobre la vía leptina-melanocortina

Childhood obesity is a growing health problem associated with significant physical and psychological morbidity at an early age. Obesity is a multifactorial disease in the majority of cases caused by an interaction of certain genetic polymorphisms and the environment. In only 5% of the patients it is related to specific gene mutations in some cases resulting in very rare Mendelian syndromes classified as monogenic obesity. The majority of these genes are involved in the hunger-satiety regulation in the central nervous system, in which the leptin-melanocortin axis plays a fundamental role. Clinically, these forms of obesity present at an early age, are severe, and are associated with eating disorders and endocrine alterations. A mutation in the melanocortine-4 receptor (MC4R) gene is the most common cause of early-onset severe monogenic obesity. The aim of this review was to provide an update of the different forms of early-onset monogenic obesity, focusing on the etiopathogenicity, main clinical features, and therapeutic approach. The management of these patients is still a challenge as specific treatment is only available for one type of monogenic obesity. For the remaining types new molecules that act on the leptin-melanocortin pathway are currently being investigated

Atividade da butirilcolinesterase e fatores de risco cardiovascular em adolescentes obesos submetidos a um programa de exercícios físicos / Butyrylcholinesterase activity and cardiovascular risk factors in obese adolescents submitted to an exercise program

OBJETIVO: Avaliar o efeito de 12 semanas de exercícios físicos em variáveis associadas a fatores de risco cardiovascular e na atividade da butirilcolinesterase (BChE) em adolescentes obesos. SUJEITOS E MÉTODOS: A amostra foi composta por 24 obesos e 51 eutróficos controles. Inicialmente e após 12 semanas foram avaliados: peso, estatura, IMC, circunferência abdominal (CA), percentual de gordura (%G), consumo máximo de oxigênio (VO2máx), pressão arterial sistólica (PAS) e diastólica (PAD), glicemia (GLI) e insulinemia (INS) basal e após 120 min, triacilglicerol (TG), colesterol total (CT), colesterol LDL, colesterol HDL e a atividade da BChE (kU/l). RESULTADOS: Após a intervenção, houve redução significativa no IMC, CA, %G, PAD, PAD, TG, GLI 120, INS, INS 120 min e na atividade da BChE. CONCLUSÃO: A redução da atividade da BChE, observada após a intervenção, foi acompanhada da redução de variáveis associadas a risco cardiovascular e à obesidade, indicando que a BChE pode ser utilizada como marcador secundário para os riscos associados à obesidade precoce.

OBJECTIVE: To evaluate the effect of 12 weeks of physical exercise (PE) on cardiovascular risk factors and BChE activity in obese adolescents. SUBJECTS AND METHODS: The sample consisted of 24 obese adolescents and 51 normal weight controls. The following variables were measured in the initial stage and after 12 weeks: weight, height, BMI, waist circumference (WC), fat percentage (% F), maximal oxygen uptake (VO2max), systolic (SBP) and diastolic (DBP) blood pressure, glucose (GLY) and insulin (INS) at baseline and after 120 min, triacylglycerol (TG), total cholesterol (TC), LDL cholesterol, HDL cholesterol, and BChE activity (kU/l). RESULTS: After the intervention, there was significant reduction in BMI, WC, %F, TG, GLI 120, INS 120 min, and BChE activity. CONCLUSION: The reduction in BChE activity, observed after physical exercise, was accompanied by the reduction of the variables associated with cardiovascular risk and obesity, indicating that BChE can be used as a secondary marker for the risk associated with early onset obesity.