Protective Association of APOC1/rs4420638 with Risk of Obesity: A case-control Study in Portuguese Children.

The association of the rs4420638 polymorphism, near the APOC1 gene, was examined with the risk of obesity among Portuguese children. A sample of 446 Portuguese individuals (231 boys and 215 girls) of European descent, aged 3.2 to 13.7 years old (mean age: 7.98 years), were selected to conduct a case-control study. Body mass index (BMI), BMI Z-scores, and waist circumference were calculated. Genotyping was performed by real time PCR using a pre-designed TaqMan probe. Logistic regression and the nonparametric Mann-Whitney test were used to test the associations. The association results revealed a significant protective effect from the minor G-allele of SNP rs4420638 against obesity, with an odds ratio (OR) of 0.619 (95% CI 0.421-0.913; p = 0.0155) in the additive model, and OR of 0.587 (95% CI 0.383-0.9; p = 0.0145) in the dominant model. Moreover, comparing genotype groups (AA vs. AG + GG), significantly lower values (p < 0.05) for the anthropometric traits weight, height, BMI, BMI Z-score and waist circumference, were observed in the carriers of allele G. The present study provides further evidence for the APOE/APOC1 candidate-region association with the risk of obesity. This was the first study to describe the protective association of the rs4420638 minor G-allele against obesity in childhood exclusively.

Differential sex-association between PCSK1 polymorphisms and obesity risk in Portuguese children.

OBJECTIVES: The proprotein convertase subtilisin/Kexin type 1 gene (PCSK1) is implicated in hypothalamic appetite control. Several studies have addressed the relationship between PCSK1 polymorphisms and obesity, although conflicting results were observed. We tested the potential association of four PCSK1 variants with the risk of overweight/obesity and related variables in Portuguese children. METHODS: This is a case-control study, where four PCSK1 variants, rs6230 (c.-101T>C), rs6232 (p.N221D), rs6235 (p.S690T), and rs3811942 (c.*265T>C), were analyzed in Portuguese children (aged 5-13 years-old). Anthropometric measures were objectively collected and used to provide weight-for-age, height-for-age, and body mass index (BMI) for age. The indices generated were compared to standard reference values of WHO to obtain the corresponding Z-scores. RESULTS: Logistic regression, in the dominant model, revealed no significant associations between the four individual PCSK1 variants and the risk of overweight/obesity in the total population. However, stratifying the sample by sex, a marginally significant association was found between the rs6235 minor C-allele and increased overweight/obesity in boys (n = 345) (OR 1.55 [1.01-2.38] p = .044), but not in girls (n = 340) (OR 0.73 [0.46-1.14] p = .169). Consistently, boys with genotype GG presented lower BMI Z-score (0.62) when compared to those with the genotypes GC + CC (1.04). Testing for different effects in males versus females, a significant interaction was found between the rs6235 polymorphism and sex for BMI Z-score (p = .025). CONCLUSIONS: Results of this study suggest for a sex-differentiated association between PCSK1 rs6235 and overweight/ obesity in Portuguese children.

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.

Immune Deficiency in Jacobsen Syndrome: Molecular and Phenotypic Characterization.

Jacobsen syndrome or JBS (OMIM #147791) is a contiguous gene syndrome caused by a deletion affecting the terminal q region of chromosome 11. The phenotype of patients with JBS is a specific syndromic phenotype predominately associated with hematological alterations. Complete and partial JBS are differentiated depending on which functional and causal genes are haploinsufficient in the patient. We describe the case of a 6-year-old Bulgarian boy in which it was possible to identify all of the major signs and symptoms listed by the Online Mendelian Inheritance in Man (OMIM) catalog using the Human Phenotype Ontology (HPO). Extensive blood and marrow tests revealed the existence of thrombocytopenia and leucopenia, specifically due to low levels of T and B cells and low levels of IgM. Genetic analysis using whole-genome single nucleotide polymorphisms (SNPs)/copy number variations (CNVs) microarray hybridization confirmed that the patient had the deletion arr[hg19]11q24.3q25(128,137,532-134,938,470)x1 in heterozygosis. This alteration was considered causal of partial JBS because the essential BSX and NRGN genes were not included, though 30 of the 96 HPO identifiers associated with this OMIM were identified in the patient. The deletion of the FLI-1, ETS1, JAM3 and THYN1 genes was considered to be directly associated with the immunodeficiency exhibited by the patient. Although immunodeficiency is widely accepted as a major sign of JBS, only constipation, bone marrow hypocellularity and recurrent respiratory infections have been included in the HPO as terms used to refer to the immunological defects in JBS. Exhaustive functional analysis and individual monitoring are required and should be mandatory for these patients.

Variants in the Obesity-Linked FTO gene locus modulates psychopathological features of patients with Anorexia Nervosa.

Our aim was to determine whether variability in the fat mass obesity (FTO) gene locus, consistently related to obesity, affects the risk of eating disorders (ED) and/or the psychopathology displayed by these patients. We analyzed 26 tag-single nucleotide polymorphisms (SNPs) that capture FTO variability in 352 ED patients [233 with Anorexia Nervosa (AN) and 119 with binge-eating] and 396 controls. Psychopathological symptoms and traits were evaluated by the Eating Disorders Inventory Test 2 (EDI-2) and Symptoms Checklist 90 Revised (SCL-90R) questionnaires. No associations were found for ED risk. The rs7205987 CC genotype correlated with higher scores in all but one of the EDI-2 scales in the AN group. Associations with Bulimia (p = 0.0019) and Interoceptive Awareness (p = 0.00007) retained significance after False Discovery Rate (FDR) correction for multiple testing. A 3-SNP sliding window analysis showed that FTO haplotypes were again highly associated with Interoceptive Awareness (rs9921255/rs6499662/rs7205987 haplotype; FDR-q = 0.04), Bulimia (rs1125338/rs2192872/rs708258; FDR-q = 0.00037), and Maturity Fears (rs708258/rs12599672/rs11076017; FDR-q = 0.041). In addition, a distal region of the gene between rs9924877 (position 53947509) and rs2192872 (54040715) was linked to Anxiety, Depression and Phobic Anxiety in AN patients, with FDR-q values ranging from 0.023 to 0.045. The results suggest that the FTO gene might be an important locus regarding traits and psychopathological symptoms often displayed by AN patients.

Variability in cannabinoid receptor genes is associated with psychiatric comorbidities in anorexia nervosa.

PURPOSE: The endocannabinoid system plays a key role in eating behavior regulating appetite and reward mechanisms, but the impact of its genetic variability has been scarcely studied in Anorexia Nervosa (AN). We aimed to analyze the association of genetic variants in cannabinoid receptors with the risk for AN and with psychiatric comorbidities that are commonplace in these patients. METHODS: We screened 221 AN patients and 396 controls for 14 tag-SNPs in the CNR1 and CNR2 genes, coding for cannabinoids receptors CB1 and CB2, respectively. Patients were diagnosed according to DSM-5 criteria and interviewed with the SCL-90R and the EDI-2 inventories to identify AN-coupled and general psychopathology. RESULTS: None of the tag-SNPs was significantly related to AN risk. However, the rs806369-TT genotype and haplotype rs806368/rs1049353/rs806369 of CNR1 were respectively associated with lower weight (mean difference = - 4.92 kg, FDR-q = 0.044) and BMI (FDR-q = 0.042) in AN patients. CNR1 rs806374-TT and CNR2 rs3003335-AA and rs6658703-GG genotypes correlated with higher scores in the Positive Symptom Distress Index (PSDI, FDR-q = 0.011 and 0.009, respectively). These three genotypes were also linked to increased Hostility in the patients (FDR-q < 0.05). Remarkably, a proximal area of the CNR1 gene locus (positions 88,143,916-88,149,832) correlated with PSDI, Hostility, Asceticism and EDI-2 total scores after correcting by multiple testing (FDR-q < 0.05 in all instances). Finally, significant CNR1/CNR2 epistasis was observed in relation to Hostility (p < 0.01) and Maturity Fears (p < 0.001). CONCLUSION: The CNR1 and CNR2 genes, coding for cannabinoid receptors, may constitute important loci regarding psychiatric comorbidities in AN patients. LEVEL III: Evidence obtained from well-designed cohort or case-control analytic studies.

Physical activity and the association between the FTO rs9939609 polymorphism and obesity in Portuguese children aged 3 to 11 years.

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.

Genetic screening for MC4R gene identifies three novel mutations associated with severe familiar obesity in a cohort of Spanish individuals.

MC4R gene is a hypothalamic satiety control mediator in which mutations cause a monogenic form of obesity. The aim of this study was to perform a genetic screening to identify variations in the entire region of MC4R gene. A total of 236 unrelated and severely obese patients (BMI ≥ 40 kg/m2) with Spanish ancestry and severe overweight familiar history have been enrolled into the study. Seven MC4R gene variants were identified in the heterozygous state in 21 patients. Coding variants p.Thr101Ile and p.Ala259Asp are new and variants p.Ser30Phe, p.Val103Ile and p.Ile251Leu were previously described. Two variants have been also observed in the promoter region of the MC4R gene; the c.-24G>A mutation, described for the first time, and the known c.-178A>C variant. Both in silico and family segregation analysis confirm the correlation between novel identified mutations in MC4R gene and obesity development. The correlation between the four variants (c.-24G>A, p.Thr101Ile, p.Ala259Asp and p.Ser30Phe) and the obesity phenotype, therefore, allows the conclusion that all of the four mutations cause a monogenic form of obesity.

The effect of copy number variations in chromosome 16p on body weight in patients with intellectual disability.

Syndromic monogenic obesity is a rare and severe early-onset form of obesity. It is characterized by intellectual disability, congenital malformations, and/or dysmorphic facies. The diagnosis of patients is challenging due to the genetic heterogenicity of this condition. However, the use of microarray technology in combination with public databases has been successful on genotype-phenotype correlations, especially for body mass index (BMI) alteration. In this study, the relationship between copy number variations (CNVs) detected by microarray mapping on 16p region and BMI alterations in syndromic patients were assessed. In order to achieve this goal, 680 unrelated Spanish children with intellectual disability were included. 16p region was characterized by using microarray platforms. All detected variants were classified as: (I) one previously non-described 10-Mb duplication in 16p13.2p12.3 region considered causal of intellectual disability and severe overweight, and (II) eleven 16p11.2 CNVs of low prevalence but with recurrence in syndromic patients with severe BMI alteration (nine proximal and two distal). Proximal 16p11.2 CNVs have a dose-dependent effect: underweight in carriers of duplication and obesity in carriers of deletion. KCTD13 was identified as a possible candidate gene for BMI alteration on proximal syndromes, whereas SH2B1 gene was identified as candidate for distal syndromes. The results shown in this paper suggest that syndromic patients could constitute a reliable model to evaluate hypothalamic satiety and obesity disorders as well as generate a wide expectation for primary prevention of comorbidities. Furthermore, 16p13.2p12.3 showed to be an important region on the regulation of body fatness.

The contribution of genetics and environment to obesity.

Background: Obesity is a global health problem mainly attributed to lifestyle changes such as diet, low physical activity or socioeconomics factors. However, several evidences consistently showed that genetics contributes significantly to the weight-gain susceptibility. Sources of data: A systematic literature search of most relevant original, review and meta-analysis, restricted to English was conducted in PubMed, Web of Science and Google scholar up to May 2017 concerning the contribution of genetics and environmental factors to obesity. Areas of agreement: Several evidences suggest that obesogenic environments contribute to the development of an obese phenotype. However, not every individual from the same population, despite sharing the same obesogenic environment, develop obesity. Areas of controversy: After more than 10 years of investigation on the genetics of obesity, the variants found associated with obesity represent only 3% of the estimated BMI-heritability, which is around 47-80%. Moreover, genetic factors per se were unable to explain the rapid spread of obesity prevalence. Growing points: The integration of multi-omics data enables scientists having a better picture and to elucidate unknown pathways contributing to obesity. Areas timely for developing research: New studies based on case-control or gene candidate approach will be important to identify new variants associated with obesity susceptibility and consequently unveiling its genetic architecture. This will lead to an improvement of our understanding about underlying mechanisms involved in development and origin of the actual obesity epidemic. The integration of several omics will also provide insights about the interplay between genes and environments contributing to the obese phenotype.

Influence of TFAP2B and KCTD15 genetic variability on personality dimensions in anorexia and bulimia nervosa.

INTRODUCTION: TFAP2B and KCTD15 are obesity-related genes that interact to regulate feeding behavior. We hypothesize that variability in these loci, isolated or in combination, could also be related to the risk of eating disorders (ED) and/or associated psychological traits. METHODS: We screened 425 participants (169 ED patients, 75 obese subjects, and 181 controls) for 10 clinically relevant and tag single-nucleotide polymorphisms (SNPs) in KCTD15 and TFAP2B by the Sequenom MassARRAY platform and direct sequencing. Psychometric evaluation was performed with EDI-2 and SCL-90R inventories. RESULTS: The KCTD15 rs287103 T variant allele was associated with increased risk of bulimia nervosa (BN) (OR = 4.34 [1.47-29.52]; p = .003) and with scores of psychopathological scales of these patients. Haplotype *6 in KCTD15 was more frequent in controls (OR = 0.40 [0.20-0.80], p = .009 for anorexia nervosa), while haplotype *4 in TFAP2B affected all three scales of the SCL-90R inventory in BN patients (p ≤ .01). Epistasis analyses revealed relevant interactions with body mass index of BN patients (p < .001). Genetic profiles in obese patients did not significantly differ from those found in ED patients. CONCLUSIONS: This is the first study that evaluates the combined role of TFAP2B and KCTD15 genes in ED. Our preliminary findings suggest that the interaction of genetic variability in these loci could influence the risk for ED and/or anthropometric and psychological parameters.

Polymorphisms in the SNRPN gene are associated with obesity susceptibility in a Spanish population.

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 < 0.03). The diversity haplotype distribution among cases and controls identified the combination rs12905653-T/rs8028366-A/rs4028395-T as being strongly and inversely associated with obesity (odds ratio = 0.49; p = 0.0006). A genetic risk score was built based on rs12905653, rs1391516 and rs2047433 SNPs and each unit increase in genetic risk score increased the obesity risk by 49% (odds ratio = 1.49, 95% confidence interval = 1.24-1.80). CONCLUSIONS: To our knowledge, this is the first study reporting an association between variability in the SNRPN gene and the risk of being obese. Interestingly, it was the major allele of each SNP that was found to be associated with the risk of weight gain. Further studies analyzing this locus and the possible additive deleterious capability of SNP combinations could be useful for demonstrating the development of obesity.

Endocrine Disrupting Chemicals, Transgenerational Epigenetics and Metabolic Diseases.

Exposure to environmental chemicals can produce effects on the endocrine system through epigenetic mechanisms. These can considerably decrease or increase the sensitivity of multiple hormones depending on the dose, route, or time of exposure. The exposure of endocrine disrupting chemicals (EDCs) during the in utero period could be a critical window, altering the epigenome profile. Recently, several researchers suggest a role of EDCs in the obesity epidemic. In this brief review, we focused on how four EDCs (bisphenol A, dichlorodiphenyltrichloroethane, di-(2-ethylhexyl) phthalate and tributyltin) may underlay transgenerational epigenetic effects. We also discuss the adipogenesis signaling pathway and the impact of exposure to individual or mixtures of EDCs on the developing endocrine system. Understanding the molecular determinants of epigenetic memory across generations will provide essential insight into how environmental exposure can affect the health of individuals, as well as subsequent generations.

Re-establishing ataxin-2 downregulates translation of mutant ataxin-3 and alleviates Machado-Joseph disease.

Machado-Joseph disease is a progressive neurodegenerative disorder associated with the polyQ-expanded ataxin-3 (encoded by ATXN3), for which no therapy is available. With the aim of clarifying the mechanism of neurodegeneration, we hypothesized that the abnormally long polyQ tract would interact aberrantly with ataxin-2 (encoded by ATXN2), another polyQ protein whose function has recently been linked to translational regulation. Using patient's samples and cellular and animal's models we found that in Machado-Joseph disease: (i) ataxin-2 levels are reduced; and (ii) its subcellular localization is changed towards the nucleus. Restoring ataxin-2 levels by lentiviral-mediated overexpression: (i) reduced mutant ataxin-3 levels; and (ii) rescued behaviour defects and neuropathology in a transgenic mouse model of Machado-Joseph disease. Conversely (i) mutating the ataxin-2 motif that enables binding to its natural interactor and translation activator poly(A)-binding protein; or (ii) overexpressing poly(A)-binding protein, had opposite effects, increasing mutant ataxin-3 translation and aggregation. This work suggests that in Machado-Joseph disease, mutant ataxin-3 drives an abnormal reduction of ataxin-2 levels, which overactivates poly(A)-binding protein, increases translation of mutant ataxin-3 and other proteins and aggravates Machado-Joseph disease. Re-establishment of ataxin-2 levels reduces mutant ataxin-3 and alleviates Machado-Joseph disease pathogenesis opening a new avenue for therapeutic intervention in this and potentially other polyQ disorders.

Current review of genetics of human obesity: from molecular mechanisms to an evolutionary perspective.

It is well-known that obesity is a complex multifactorial and heterogeneous condition with an important genetic component. Recently, major advances in obesity research emerged concerning the molecular mechanisms contributing to the obese condition. This review outlines several studies and data concerning the genetics and other important factors in the susceptibility risk to develop obesity. Based in the genetic etiology three main categories of obesity are considered: monogenic, syndromic, and common obesity. For the monogenic forms of obesity, the gene causing the phenotype is clearly identified, whereas for the common obesity the loci architecture underlying the phenotype is still being characterized. Given that, in this review we focus mainly in this obesity form, reviewing loci found until now by genome-wide association studies related with the susceptibility risk to develop obesity. Moreover, we also detail the obesity-related loci identified in children and in different ethnic groups, trying to highlight the complexity of the genetics underlying the common obese phenotype. Importantly, we also focus in the evolutionary hypotheses that have been proposed trying to explain how natural selection favored the spread of genes that increase the risk for an obese phenotype and how this predisposition to obesity evolved. Other factors are important in the obesity condition, and thus, we also discuss the epigenetic mechanisms involved in the susceptibility and development of obesity. Covering all these topics we expect to provide a complete and recent perspective about the underlying mechanisms involved in the development and origin of obesity. Only with a full understanding of the factors and mechanisms contributing to obesity, it will be possible to provide and allow the development of new therapeutic approaches to this condition.

Melanocortin-4 receptor gene variants are not associated with binge-eating behavior in nonobese patients with eating disorders.

We aimed to determine whether variability in the melanocortin-4 receptor (MC4R) gene, predisposing to hyperphagia and obesity, may also be present in nonobese patients with binge-eating behavior or be related to anthropometric or psychopathological parameters in these patients. The coding region of the MC4R gene was sequenced in nonobese patients with binge-eating behavior diagnosed with bulimia nervosa or binge-eating disorder (n=77); individuals with severe early-onset obesity (n=170); and lean women with anorexia nervosa (n=20). A psychometric evaluation (Eating Disorders Inventory-2 and Symptom Checklist 90 Revised inventories) was carried out for all the patients with eating disorders. In the obesity group, 10 different variants were identified, whereas in the binge-eating patients, only two individuals with bulimia nervosa were found to carry the I251L polymorphism, which did not correlate with weight, BMI, or psychopathological features. We found no evidence that mutations in the MC4R gene are associated with binge-eating behavior in nonobese eating disorder patients.

RNA interference mitigates motor and neuropathological deficits in a cerebellar mouse model of Machado-Joseph disease.

Machado-Joseph disease or Spinocerebellar ataxia type 3 is a progressive fatal neurodegenerative disorder caused by the polyglutamine-expanded protein ataxin-3. Recent studies demonstrate that RNA interference is a promising approach for the treatment of Machado-Joseph disease. However, whether gene silencing at an early time-point is able to prevent the appearance of motor behavior deficits typical of the disease when initiated before onset of the disease had not been explored. Here, using a lentiviral-mediated allele-specific silencing of mutant ataxin-3 in an early pre-symptomatic cerebellar mouse model of Machado-Joseph disease we show that this strategy hampers the development of the motor and neuropathological phenotypic characteristics of the disease. At the histological level, the RNA-specific silencing of mutant ataxin-3 decreased formation of mutant ataxin-3 aggregates, preserved Purkinje cell morphology and expression of neuronal markers while reducing cell death. Importantly, gene silencing prevented the development of impairments in balance, motor coordination, gait and hyperactivity observed in control mice. These data support the therapeutic potential of RNA interference for Machado-Joseph disease and constitute a proof of principle of the beneficial effects of early allele-specific silencing for therapy of this disease.

Novel variants in the MC4R and LEPR genes among severely obese children from the Iberian population.

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.

Association study of common polymorphisms in MSRA, TFAP2B, MC4R, NRXN3, PPARGC1A, TMEM18, SEC16B, HOXB5 and OLFM4 genes with obesity-related traits among Portuguese children.

At least 52 genetic loci were associated with obesity-related traits. However, little is known about the genetic basis of obesity among children. This study aims to test whether 10 polymorphisms in obesity-related genes methionine sulfoxide reductase A (MSRA), transcription factor AP-2 beta (TFAP2B), melanocortin 4 receptor (MC4R), neurexin 3 (NRXN3), peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PPARGC1A), transmembrane protein 18 (TMEM18), homolog of S. cerevisiae Sec16 (SEC16B), homeobox B5 (HOXB5) and olfactomedin 4 (OLFM4) are associated with the risk of obesity in Portuguese children. A total of 730 children aging from 6 to 12 years old, recruited randomly from public schools in Portugal, were analysed. Anthropometric measurements were obtained and children were classified into three phenotypic groups, normal weight (n=256), overweight (n=320) and obese (n=154), according to the International Obesity Task Force cutoffs. Polymorphisms were genotyped by allelic discrimination TaqMan assays. The MC4R rs12970134 polymorphism was nominally associated with body mass index (BMI) (P=0.035), BMI Z-score (P=0.043) and waist circumference (P=0.020), and borderline associated with weight (P=0.053). Near nominal associations were also found for the PPARGC1A rs8192678 polymorphism with weight (P=0.061), and for the MSRA rs545854 polymorphism with BMI (P=0.055) and BMI Z-score (P=0.056). Furthermore, logistic regression showed that MC4R rs12970134 and TFAP2B rs987237 were nominally, respectively, associated (P=0.029) and borderline associated (P=0.056) with the obese phenotype. This study highlighted the possible association of MC4R, PPARGC1A, MSRA and TFAP2B polymorphisms with several obesity-related traits in a sample of Portuguese children. The two significant associated TFAP2B rs987237 and MC4R rs12970134 polymorphisms showed an opposite direction of effect to that in the original reports.

Beclin 1 mitigates motor and neuropathological deficits in genetic mouse models of Machado-Joseph disease.

Machado-Joseph disease or spinocerebellar ataxia type 3, the most common dominantly-inherited spinocerebellar ataxia, results from translation of the polyglutamine-expanded and aggregation prone ataxin 3 protein. Clinical manifestations include cerebellar ataxia and pyramidal signs and there is no therapy to delay disease progression. Beclin 1, an autophagy-related protein and essential gene for cell survival, is decreased in several neurodegenerative disorders. This study aimed at evaluating if lentiviral-mediated beclin 1 overexpression would rescue motor and neuropathological impairments when administered to pre- and post-symptomatic lentiviral-based and transgenic mouse models of Machado-Joseph disease. Beclin 1-mediated significant improvements in motor coordination, balance and gait with beclin 1-treated mice equilibrating longer periods in the Rotarod and presenting longer and narrower footprints. Furthermore, in agreement with the improvements observed in motor function beclin 1 overexpression prevented neuronal dysfunction and neurodegeneration, decreasing formation of polyglutamine-expanded aggregates, preserving Purkinje cell arborization and immunoreactivity for neuronal markers. These data show that overexpression of beclin 1 in the mouse cerebellum is able to rescue and hinder the progression of motor deficits when administered to pre- and post-symptomatic stages of the disease.