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Bonnefond A, Keller R, Meyre D, Stutzmann F, Thuillier D, Stefanov DG, Froguel P, Horber FF, Kral JG. Eating Behavior, Low-Frequency Functional Mutations in the Melanocortin-4 Receptor (MC4R) Gene, and Outcomes of Bariatric Operations: A 6-Year Prospective Study. Diabetes Care 2016; 39:1384-92. [PMID: 27222505 DOI: 10.2337/dc16-0115] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/02/2016] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Data on the effects of eating behavior and genetics on outcomes of gastrointestinal surgery for diabesity have been sparse, often flawed, and controversial. We aimed to assess long-term outcomes of bariatric operations in patients characterized for eating behavior and rare mutations in the melanocortin-4 receptor (MC4R) gene, which is strongly implicated in energy balance. RESEARCH DESIGN AND METHODS Between 1996 and 2005, 1,264 severely obese Swiss patients underwent current laparoscopic adjustable gastric banding, gastroduodenal bypass, or a hybrid operation. Of these, 872 patients were followed for a minimum of 6 years and were screened for MC4R mutations. Using regression models, we studied relationships between eating behavior and MC4R mutations and postoperative weight loss, complications, and reoperations after 6 years. RESULTS At baseline, rare functional MC4R mutation carriers exhibited a significantly higher prevalence of binge eating disorder (BED) or loss-of-control eating independent of age, sex, and BMI. Six years after bariatric surgery, the mutation carriers had more major complications than wild-type subjects independent of age, baseline BMI, sex, operation type, and weight loss. Furthermore, high baseline BMI, male sex, BED, and functional MC4R mutations were independent predictors of higher reoperation rates. CONCLUSIONS Sequencing of MC4R and eating typology, combined with stratification for sex and baseline BMI, might significantly improve patient allocation to banding or bypass operations for diabesity as well as reduce both complication and reoperation rates.
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Affiliation(s)
- Amélie Bonnefond
- CNRS UMR 8199, Lille Pasteur Institute, Lille, France Lille University, Lille, France European Genome Institute for Diabetes, FR 3508, Lille, France Department of Genomics of Common Disease, School of Public Health, Hammersmith Hospital, Imperial College London, London, U.K
| | - Ramsi Keller
- Department of Internal Medicine, Landesspital Liechtenstein, Vaduz, Liechtenstein Dr. Horber Adipositas Stiftung, Zurich, Switzerland
| | - David Meyre
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Fanny Stutzmann
- CNRS UMR 8199, Lille Pasteur Institute, Lille, France Lille University, Lille, France European Genome Institute for Diabetes, FR 3508, Lille, France
| | - Dorothée Thuillier
- CNRS UMR 8199, Lille Pasteur Institute, Lille, France Lille University, Lille, France European Genome Institute for Diabetes, FR 3508, Lille, France
| | - Dimitre G Stefanov
- Scientific Computing Center and Departments of Surgery, Medicine, and Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY
| | - Philippe Froguel
- CNRS UMR 8199, Lille Pasteur Institute, Lille, France Lille University, Lille, France European Genome Institute for Diabetes, FR 3508, Lille, France Department of Genomics of Common Disease, School of Public Health, Hammersmith Hospital, Imperial College London, London, U.K.
| | - Fritz F Horber
- Department of Internal Medicine, Landesspital Liechtenstein, Vaduz, Liechtenstein Dr. Horber Adipositas Stiftung, Zurich, Switzerland University of Bern, Bern, Switzerland
| | - John G Kral
- Scientific Computing Center and Departments of Surgery, Medicine, and Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY
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Bonnefond A, Raimondo A, Stutzmann F, Ghoussaini M, Ramachandrappa S, Bersten DC, Durand E, Vatin V, Balkau B, Lantieri O, Raverdy V, Pattou F, Van Hul W, Van Gaal L, Peet DJ, Weill J, Miller JL, Horber F, Goldstone AP, Driscoll DJ, Bruning JB, Meyre D, Whitelaw ML, Froguel P. Loss-of-function mutations in SIM1 contribute to obesity and Prader-Willi-like features. J Clin Invest 2013; 123:3037-41. [PMID: 23778136 DOI: 10.1172/jci68035] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 04/18/2013] [Indexed: 11/17/2022] Open
Abstract
Sim1 haploinsufficiency in mice induces hyperphagic obesity and developmental abnormalities of the brain. In humans, abnormalities in chromosome 6q16, a region that includes SIM1, were reported in obese children with a Prader-Willi-like syndrome; however, SIM1 involvement in obesity has never been conclusively demonstrated. Here, SIM1 was sequenced in 44 children with Prader-Willi-like syndrome features, 198 children with severe early-onset obesity, 568 morbidly obese adults, and 383 controls. We identified 4 rare variants (p.I128T, p.Q152E, p.R581G, and p.T714A) in 4 children with Prader-Willi-like syndrome features (including severe obesity) and 4 other rare variants (p.T46R, p.E62K, p.H323Y, and p.D740H) in 7 morbidly obese adults. By assessing the carriers' relatives, we found a significant contribution of SIM1 rare variants to intra-family risk for obesity. We then assessed functional effects of the 8 substitutions on SIM1 transcriptional activities in stable cell lines using luciferase gene reporter assays. Three mutations showed strong loss-of-function effects (p.T46R, p.H323Y, and p.T714A) and were associated with high intra-family risk for obesity, while the variants with mild or no effects on SIM1 activity were not associated with obesity within families. Our genetic and functional studies demonstrate a firm link between SIM1 loss of function and severe obesity associated with, or independent of, Prader-Willi-like features.
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Affiliation(s)
- Amélie Bonnefond
- European Genomic Institute for Diabetes, Lille Pasteur Institute, Lille, France
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Rouskas K, Meyre D, Stutzmann F, Paletas K, Papazoglou D, Vatin V, Marchand M, Kouvatsi A, Froguel P. Loss-of-function mutations in MC4R are very rare in the Greek severely obese adult population. Obesity (Silver Spring) 2012; 20:2278-82. [PMID: 22447289 DOI: 10.1038/oby.2012.77] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Melanocortin-4 receptor (MC4R) loss-of-function mutations are the commonest genetic cause of human monogenic obesity, so far. The contribution of MC4R coding mutations to severe obesity in the high-obesity prone Greek population has not been investigated to date. We determined the MC4R coding sequence of 510 obese and 469 lean control subjects of Greek origin, and we estimated the prevalence and the penetrance on obesity of MC4R loss-of-function mutations. The functional impact of novel nonsynonymous variants detected was investigated in vitro. We found two novel synonymous mutations (L23L and I102I), four nonsynonymous mutations (T112M, S127L, N274S, and S295L), and two polymorphisms (V103I and I251L) previously described in literature. We also detected a novel mutation (L207V) in a severely obese 69-year-old female patient, although the mutation did not cosegregate with obesity in the corresponding pedigree and had no functional consequences on MC4R protein function. Loss-of-function mutations represented 75% of all nonsynonymous rare mutations identified among lean carriers and only 25% among obese subjects (P = 0.0001). The prevalence of loss-of-function mutations was lower in the obese group than in lean control subjects (0.20 vs. 0.64%) but this difference was not significant. Therefore, the estimated penetrance of deleterious MC4R mutations was very low (6.3%) in heterozygous Greek carriers of MC4R loss-of-function mutations. Our data suggest that MC4R loss-of-function mutations are rare in the Greek population. MC4R genetic deficiency is unlikely to explain the high propensity to develop severe obesity in this specific population.
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Affiliation(s)
- Konstantinos Rouskas
- Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Marion V, Stutzmann F, Gérard M, De Melo C, Schaefer E, Claussmann A, Hellé S, Delague V, Souied E, Barrey C, Verloes A, Stoetzel C, Dollfus H. Exome sequencing identifies mutations inLZTFL1, a BBSome and smoothened trafficking regulator, in a family with Bardet–Biedl syndrome with situs inversus and insertional polydactyly. J Med Genet 2012; 49:317-21. [DOI: 10.1136/jmedgenet-2012-100737] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Schaefer E, Zaloszyc A, Lauer J, Durand M, Stutzmann F, Perdomo-Trujillo Y, Redin C, Bennouna Greene V, Toutain A, Perrin L, Gérard M, Caillard S, Bei X, Lewis RA, Christmann D, Letsch J, Kribs M, Mutter C, Muller J, Stoetzel C, Fischbach M, Marion V, Katsanis N, Dollfus H. Mutations in SDCCAG8/NPHP10 Cause Bardet-Biedl Syndrome and Are Associated with Penetrant Renal Disease and Absent Polydactyly. Mol Syndromol 2011; 1:273-281. [PMID: 22190896 DOI: 10.1159/000331268] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2011] [Indexed: 11/19/2022] Open
Abstract
The ciliopathies are an expanding group of disorders caused by mutations in genes implicated in the biogenesis and function of primary cilia. Bardet-Biedl syndrome (BBS) is a model ciliopathy characterized by progressive retinal degeneration, obesity, polydactyly, cognitive impairment, kidney anomalies and hypogonadism. Mutations in SDCCAG8(NPHP10) were described recently in patients with nephronophthisis and retinal degeneration (Senior-Loken syndrome; SLS). Given the phenotypic and genetic overlap between known ciliopathy genes, we hypothesized that mutations in SDCCAG8 might also contribute alleles to more severe, multisystemic ciliopathies. We performed genetic and phenotypic analyses of 2 independent BBS cohorts. Subsequent to mutation screening, we made a detailed phenotypic analysis of 5 families mutated for SDCCAG8 (3 homozygous and 2 compound heterozygous mutations) and conducted statistical analyses across both cohorts to examine possible phenotype-genotype correlations with mutations at this locus. All patients with mutations in SDCCAG8 fulfilled the diagnostic criteria for BBS (retinal degeneration, obesity, cognitive defects, renal failure, hypogonadism). Interestingly, none of the patients with primary SDCCAG8 mutations had polydactyly, a frequent but not obligatory BBS feature. In contrast, the same patients displayed early-onset renal failure, obesity, as well as recurrent pulmonary and ENT infections. Comparison of the phenotypes of these families with our entire BBS cohort indicated that renal impairment and absent polydactyly correlated significantly with causal SDCCAG8 mutations. Thus, SDCCAG8 mutations are sufficient to cause BBS in 1-2% of our combined cohorts, and define this gene as the sixteenth BBS locus (BBS16). The absence of polydactyly and the concomitant, apparently fully penetrant association with early kidney failure represents the first significant genotype-phenotype correlation in BBS that potentially represents an indicator for phenotype-driven priority screening and informs specific patient management.
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Affiliation(s)
- E Schaefer
- Laboratoire de Génétique Médicale EA 3949, Equipe Avenir-Inserm, Faculté de Médecine de Strasbourg, Université de Strasbourg, Strasbourg
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Mockel A, Perdomo Y, Stutzmann F, Letsch J, Marion V, Dollfus H. Retinal dystrophy in Bardet-Biedl syndrome and related syndromic ciliopathies. Prog Retin Eye Res 2011; 30:258-74. [PMID: 21477661 DOI: 10.1016/j.preteyeres.2011.03.001] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 03/03/2011] [Accepted: 03/04/2011] [Indexed: 01/26/2023]
Abstract
Primary cilia are almost ubiquitously expressed in eukaryotic cells where they function as sensors relaying information either from the extracellular environment or between two compartments of the same cell, such as in the photoreceptor cell. In ciliopathies, a continuously growing class of genetic disorders related to ciliary defects, the modified primary cilium of the photoreceptor, also known as the connecting cilium, is frequently defective. Ciliary dysfunction involves disturbances in the trafficking and docking of specific proteins involved in its biogenesis or maintenance. The main well-conserved ciliary process, intraflagellar transport (IFT), is a complex process carried out by multimeric ciliary particles and molecular motors of major importance in the photoreceptor cell. It is defective in a growing number of ciliopathies leading to retinal degeneration. Retinitis pigmentosa related to ciliary dysfunction can be an isolated feature or a part of a syndrome such as Bardet-Biedl syndrome (BBS). Research on ciliopathies and BBS has led to the discovery of several major cellular processes carried out by the primary cilium structure and has highlighted their genetic heterogeneity.
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Affiliation(s)
- A Mockel
- Laboratoire de physiopathologie des syndromes rares et héréditaires, Strasbourg, France
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Ghoussaini M, Stutzmann F, Couturier C, Vatin V, Durand E, Lecoeur C, Degraeve F, Heude B, Tauber M, Hercberg S, Levy-Marchal C, Tounian P, Weill J, Traurig M, Bogardus C, Baier LJ, Michaud JL, Froguel P, Meyre D. Analysis of the SIM1 contribution to polygenic obesity in the French population. Obesity (Silver Spring) 2010; 18:1670-5. [PMID: 20075856 PMCID: PMC2953787 DOI: 10.1038/oby.2009.468] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
SIM1 (single-minded 1) haploinsufficiency is responsible for obesity in both humans and mice, but the contribution of frequent DNA variation to polygenic obesity is unknown. Sequencing of all exons, exon/intron boundaries, 870 base pairs (bp) of the putative promoter, and 1,095 bp of the 3'UTR of SIM1 gene in 143 obese children and 24 control adults identified 13 common variants. After analysis of the linkage disequilibrium (LD) structure, association study of eight variants was performed in 1,275 obese children and severely obese adults, in 1,395 control subjects, and in 578 obesity-selected pedigrees. A nominal evidence of association was found for the nonsynonymous variant P352T C/A (rs3734354) (P = 0.01, OR = 0.81 (0.70-0.95)), the +2,004 TGA -/insT SNP (rs35180395) (P = 0.02, OR = 1.21 (1.02-1.43)), the +2,215A/G TGA SNP (rs9386126) (P = 0.002, OR = 0.81 (0.71-0.93)), and pooled childhood/adult obesity. Even though transmission disequilibrium test (TDT) further supported the association of P352T and +2,004 -/inst T with obesity, none of these nominal associations remained significant after a multiple testing Bonferroni correction. Therefore, our study excludes a major contribution of SIM1 common variants in exons, 5' and 3' UTR regions in polygenic obesity susceptibility in French Europeans.
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Affiliation(s)
- Maya Ghoussaini
- Genomics and Molecular Physiology of Metabolic Diseases, CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
| | - Fanny Stutzmann
- Genomics and Molecular Physiology of Metabolic Diseases, CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
| | - Cyril Couturier
- Genomics and Molecular Physiology of Metabolic Diseases, CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
| | - Vincent Vatin
- Genomics and Molecular Physiology of Metabolic Diseases, CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
| | - Emmanuelle Durand
- Genomics and Molecular Physiology of Metabolic Diseases, CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
| | - Cécile Lecoeur
- Genomics and Molecular Physiology of Metabolic Diseases, CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
| | - Franck Degraeve
- Genomics and Molecular Physiology of Metabolic Diseases, CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
| | - Barbara Heude
- Epidemiological and Statistical Research, INSERM U780, Villejuif, France
- University Paris-Sud, Orsay, France
| | - Maithé Tauber
- Center of Physiopathology Toulouse Purpan, INSERM U563, Children’s Hospital, CHU, Toulouse, France
| | - Serge Hercberg
- Centre of Research in Nutrition, UMR U557 INSERM, U1125 INRA, CNAM, Université Paris 13, CRNH IdF, Bobigny, France
| | - Claire Levy-Marchal
- Department of Pediatric Endocrinology and Diabetology, INSERM, U690, Paris, France
- University Paris Diderot, Paris, France
| | - Patrick Tounian
- Department of Pediatric Gastroenterology and Nutrition, Armand-Trousseau Hospital, AP-HP, Paris, France
| | - Jacques Weill
- Pediatric Endocrine Unit, Jeanne de Flandre Hospital, Lille, France
| | - Michael Traurig
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona, USA
| | - Clifton Bogardus
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona, USA
| | - Leslie J. Baier
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona, USA
| | | | - Philippe Froguel
- Genomics and Molecular Physiology of Metabolic Diseases, CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
- Department of Genomic Medicine, Hammersmith Hospital, ‘Imperial College London, London, UK
| | - David Meyre
- Genomics and Molecular Physiology of Metabolic Diseases, CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
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Walters RG, Jacquemont S, Valsesia A, de Smith AJ, Martinet D, Andersson J, Falchi M, Chen F, Andrieux J, Lobbens S, Delobel B, Stutzmann F, El-Sayed Moustafa JS, Chèvre JC, Lecoeur C, Vatin V, Bouquillon S, Buxton JL, Boute O, Holder-Espinasse M, Cuisset JM, Lemaitre MP, Ambresin AE, Brioschi A, Gaillard M, Giusti V, Fellmann F, Ferrarini A, Hadjikhani N, Campion D, Guilmatre A, Goldenberg A, Calmels N, Mandel JL, Le Caignec C, David A, Isidor B, Cordier MP, Dupuis-Girod S, Labalme A, Sanlaville D, Béri-Dexheimer M, Jonveaux P, Leheup B, Ounap K, Bochukova EG, Henning E, Keogh J, Ellis RJ, Macdermot KD, van Haelst MM, Vincent-Delorme C, Plessis G, Touraine R, Philippe A, Malan V, Mathieu-Dramard M, Chiesa J, Blaumeiser B, Kooy RF, Caiazzo R, Pigeyre M, Balkau B, Sladek R, Bergmann S, Mooser V, Waterworth D, Reymond A, Vollenweider P, Waeber G, Kurg A, Palta P, Esko T, Metspalu A, Nelis M, Elliott P, Hartikainen AL, McCarthy MI, Peltonen L, Carlsson L, Jacobson P, Sjöström L, Huang N, Hurles ME, O'Rahilly S, Farooqi IS, Männik K, Jarvelin MR, Pattou F, Meyre D, Walley AJ, Coin LJM, Blakemore AIF, Froguel P, Beckmann JS. A new highly penetrant form of obesity due to deletions on chromosome 16p11.2. Nature 2010; 463:671-5. [PMID: 20130649 PMCID: PMC2880448 DOI: 10.1038/nature08727] [Citation(s) in RCA: 345] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Accepted: 12/01/2009] [Indexed: 01/04/2023]
Affiliation(s)
- R G Walters
- Section of Genomic Medicine, Imperial College London, London W12 0NN, UK
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Stutzmann F, Tan K, Vatin V, Dina C, Jouret B, Tichet J, Balkau B, Potoczna N, Horber F, O'Rahilly S, Farooqi IS, Froguel P, Meyre D. Prevalence of melanocortin-4 receptor deficiency in Europeans and their age-dependent penetrance in multigenerational pedigrees. Diabetes 2008; 57:2511-8. [PMID: 18559663 PMCID: PMC2518504 DOI: 10.2337/db08-0153] [Citation(s) in RCA: 198] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2008] [Accepted: 06/05/2008] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Melanocortin-4 receptor (MC4R) deficiency is the most frequent genetic cause of obesity. However, there is uncertainty regarding the degree of penetrance of this condition, and the putative impact of the environment on the development of obesity in MC4R mutation carriers is unknown. RESEARCH DESIGN AND METHODS We determined the MC4R sequence in 2,257 obese individuals and 2,677 nonobese control subjects of European origin and established the likely functional impact of all variants detected. We then included relatives of probands carriers and studied 25 pedigrees, including 97 carriers and 94 noncarriers from three generations. RESULTS Of the MC4R nonsynonymous mutations found in obese subjects, 68% resulted in a loss of function in vitro. They were found in 1.72% of obese versus 0.15% of nonobesed subjects (P = 6.9 x 10(-10)). Among the families, abnormal eating behavior was more frequent in both MC4R-deficient children and adults than in noncarriers. Although BMI was inversely associated with educational status in noncarrier adults, no such relationship was seen in MC4R mutation carriers. We observed a generational effect, with a penetrance of 40% in MC4R-deficient adults aged >52 years, 60% in 18- to 52-year-old adults, and 79% in children. The longitudinal study of adult carriers showed an increasing age-dependent penetrance (37% at 20 years versus 60% at >40 years). CONCLUSIONS We have established a robust estimate of age-related penetrance for MC4R deficiency and demonstrated a generational effect on penetrance, which may relate to the development of an "obesogenic" environment. It remains to be seen whether appropriate manipulation of environmental factors may contribute to preventing the development of obesity even in those strongly genetically predisposed to it.
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Affiliation(s)
- Fanny Stutzmann
- Centre National de la Recherche Scientifique-8090, Institute of Biology, Pasteur Institute, Lille, France
| | - Karen Tan
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, U.K
| | - Vincent Vatin
- Centre National de la Recherche Scientifique-8090, Institute of Biology, Pasteur Institute, Lille, France
| | - Christian Dina
- Centre National de la Recherche Scientifique-8090, Institute of Biology, Pasteur Institute, Lille, France
| | - Béatrice Jouret
- Institut National de la Santé et de la Recherche Médicale U563, Children's Hospital, Toulouse, France
| | - Jean Tichet
- Institut inter Régional pour la Santé, La Riche, France
| | - Beverley Balkau
- Institut National de la Santé et de la Recherche Médicale U780-IFR69, Villejuif, Université Paris-Sud, Orsay, France
| | - Natascha Potoczna
- Klinik Lindberg, Winterthur, and University of Berne, Berne, Switzerland
| | - Fritz Horber
- Klinik Lindberg, Winterthur, and University of Berne, Berne, Switzerland
| | - Stephen O'Rahilly
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, U.K
| | - I. Sadaf Farooqi
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, U.K
| | - Philippe Froguel
- Centre National de la Recherche Scientifique-8090, Institute of Biology, Pasteur Institute, Lille, France
- Department of Genomic Medicine, Hammersmith Hospital, Imperial College London, London, U.K
| | - David Meyre
- Centre National de la Recherche Scientifique-8090, Institute of Biology, Pasteur Institute, Lille, France
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Ribes V, Stutzmann F, Bianchetti L, Guillemot F, Dollé P, Le Roux I. Combinatorial signalling controls Neurogenin2 expression at the onset of spinal neurogenesis. Dev Biol 2008; 321:470-81. [PMID: 18590718 DOI: 10.1016/j.ydbio.2008.06.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 05/15/2008] [Accepted: 06/03/2008] [Indexed: 11/17/2022]
Abstract
A central issue during embryonic development is to define how different signals cooperate in generating unique cell types. To address this issue, we focused on the function and the regulation of the proneural gene Neurogenin2 (Neurog2) during early mouse spinal neurogenesis. We showed that Neurog2 is first expressed in cells within the neural plate anterior to the node from the 5 somite-stage. The analysis of Neurog2 mutants established a role for this gene in triggering neural differentiation during spinal cord elongation. We identified a 798 base pair enhancer element (Neurog2-798) upstream of the Neurog2 coding sequence that directs the early caudal expression of Neurog2. Embryo culture experiments showed that Retinoic Acid (RA), Sonic hedgehog (Shh) and Fibroblast Growth Factor signals act in concert on this enhancer to control the spatial and temporal induction of Neurog2. We further demonstrated by transgenesis that two RA response elements and a Gli binding site within the Neurog2-798 element are absolutely required for its activity, strongly suggesting that the regulation of Neurog2 early expression by RA and Shh signals is direct. Our data thus support a model where signal integration at the level of a single enhancer constitutes a key mechanism to control the onset of neurogenesis.
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Affiliation(s)
- Vanessa Ribes
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Inserm U 596, CNRS UMR 7104, Université Louis Pasteur, 1 rue Laurent Friès, Illkirch, BP 10142 F-67400, France
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Stutzmann F, Vatin V, Cauchi S, Morandi A, Jouret B, Landt O, Tounian P, Levy-Marchal C, Buzzetti R, Pinelli L, Balkau B, Horber F, Bougnères P, Froguel P, Meyre D. Non-synonymous polymorphisms in melanocortin-4 receptor protect against obesity: the two facets of a Janus obesity gene. Hum Mol Genet 2007; 16:1837-44. [PMID: 17519222 DOI: 10.1093/hmg/ddm132] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The melanocortin-4 receptor (MC4R) gene pathogenic mutations are the most prevalent forms of monogenic obesity, responsible for approximately 2% of obesity cases, but its role in common obesity is still elusive. We analyzed the contribution of non-synonymous mutations V103I (rs2229616, c.307G > A) and I251L (no rs, c.751A > C) to obesity in 16 797 individuals of European origin from nine independent case-control, population-based and familial cohorts. We observed a consistent negative association of I251L variant (prevalence ranging 0.41-1.21%) with both childhood and adult class III obesity [odds ratio (OR) ranging from 0.25 to 0.76, 0.001 < P-value < 0.05] and with modulation of body mass index (BMI) in general populations, in eight out of nine studies, whereas only one study showed an association between V103I and BMI. Meta-analyses of previous published data with the current ones provided strong evidence of the protective effect of I251L toward obesity (OR = 0.52, P = 3.58 10-5), together with a modest negative association between V103I and obesity (OR = 0.80, P = 0.002). Taken together, gain-of-function mutations I251L and V103I may be responsible for a preventive fraction of obesity of 2%, which mirrors the prevalence of monogenic obesity due to MC4R haploinsufficiency. These results also emphasize the importance of the MC4R signalling tonus to prevent obesity, even in the context of our current obesogenic environment.
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Affiliation(s)
- Fanny Stutzmann
- CNRS-8090-Institute of Biology, Pasteur Institute, Lille, France
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