title: Prevalence of mutations in LEP, LEPR, and MC4R genes in individuals with severe obesity.
abstract: Obesity is a major public health concern; despite evidence of high heritability, the genetic causes of obesity remain unclear. In this study, we assessed the presence of mutations in three genes involved in the hypothalamic leptin-melanocortin regulation pathway (leptin, LEP; leptin receptor, LEPR; and melanocortin-4 receptor, MC4R), which is important for energy homeostasis in the body, in a group of patients with severe obesity. For this study, we selected 77 patients who had undergone bariatric surgery and had a pre-operative body mass index (BMI) >35 kg/m2, early onset and a family history of being overweight. Candidate genes were screened by direct sequence analysis to search for rare genetic variations. The common LEP -2548 G/A polymorphism was also evaluated for its influence on the BMI (in obesity patients) and for obesity risk, using a case-control study involving 117 healthy individuals. Two different non-synonymous alterations in MC4R were found in two patients: the p.(Thr112Met), previously described in the literature as a probable gene involved in the obesity phenotype, and the novel p.(Tyr302Asp) variant, predicted to be pathogenic by in silico evaluations and family segregation studies. The LEP -2548 G/A polymorphism was not associated with the BMI or obesity risk. In conclusion, we have reported a novel mutation in MC4R in a family of Italian patients with severe obesity. Screening for MC4R could be important for directing the carriers of mutations towards therapy including partial agonists of the MC4R that could normalize their appetite and inhibit compulsive eating. Next-generation sequencing could be used to clarify the genetic basis of obesity in the future.
authors.affiliation: UO Dietetica Medica, Azienda Ospedaliera Universitaria Senese, Policlinico Santa Maria alle Scotte, Siena, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Paolini
authors.affiliation: MAGI Non-Profit Human Medical Genetics Institute, Rovereto, TN, Italy paolo.maltese@assomagi.org.
authors.forename: P E
authors.initials: PE
authors.lastname: Maltese
authors.affiliation: UO Dietetica Medica, Azienda Ospedaliera Universitaria Senese, Policlinico Santa Maria alle Scotte, Siena, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Del Ciondolo
authors.affiliation: Laboratory of Cellular Biochemistry and Molecular Biology-CRIBENS Catholic University of the Sacred Heart, Milan, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Tavian
authors.affiliation: Laboratory of Cellular Biochemistry and Molecular Biology-CRIBENS Catholic University of the Sacred Heart, Milan, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Missaglia
authors.affiliation: Dipartimento di Medicina Interna Scienze Endocrino Metaboliche e Biochimiche, Azienda Ospedaliera Universitaria Senese, Siena, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Ciuoli
authors.affiliation: MAGI Non-Profit Human Medical Genetics Institute, Rovereto, TN, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Zuntini
authors.affiliation: MAGI Non-Profit Human Medical Genetics Institute, Rovereto, TN, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Cecchin
authors.affiliation: MAGI Non-Profit Human Medical Genetics Institute, Rovereto, TN, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bertelli
authors.affiliation: Dipartimento di Biotecnologia, Chimica e Scienze Farmaceutiche, Università di Siena, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Pompucci
mesh_terms: D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D020738:Leptin / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D009767:Obesity, Morbid / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide; D015995:Prevalence; D044105:Receptor, Melanocortin, Type 4 / Q000235:genetics*; D054411:Receptors, Leptin / Q000235:genetics*
chemical_list: C515448:LEPR protein, human; D020738:Leptin; C470072:MC4R protein, human; D044105:Receptor, Melanocortin, Type 4; D054411:Receptors, Leptin