title: Variation analysis of beta3-adrenergic receptor and melanocortin-4 receptor genes in childhood obesity.
abstract: BACKGROUND
  Decreased energy expenditure and increased food intake are principal causes for obesity. In the present study, genotypes of beta(3)-adrenergic receptor (beta(3)AR) and of melanocortin-4 receptor (MC4R), both of which are believed to have a close link to the cause of obesity, were analyzed and compared with phenotypes of childhood obesity.
  
  
  METHODS
  Thirty-five obese children with moderate to severe obesity were enrolled. Direct sequencing of the MC4R coding region and pinpoint-polymerase chain reaction were used to detect genomic variation in the beta(3)AR gene using peripheral blood-derived DNA.
  
  
  RESULTS
  Allele frequency of Trp64Arg variation in the beta(3)AR gene in the obese subjects was 0.16, which is comparable with that in the healthy general population in eastern Asia. Comparison of phenotypical characteristics did not show a significant difference between Trp/Trp and Trp/Arg subjects. It was notable that body height SD was significantly higher in the Trp/Trp than the Trp/Arg subjects (0.93 +/- 1.0 SD vs 0.07 +/- 1.3 SD, P= 0.03). Annual weight gains were far beyond a hypothetical fat gain in an Arg64 heterozygote with decreased energy consumption, suggesting increased food intake in childhood obesity. There was, however, no variation in the MC4R gene despite thorough sequencing of the entire coding region.
  
  
  CONCLUSIONS
  The Trp64Arg variation in the beta(3)AR gene has no relationship to the degree or the incidence of childhood obesity. The majority of childhood obesity can be characterized as tall stature, more rapid weight gain than that expected by decreased energy expenditure. Further investigation is necessary in regard to the increased food intake as a major cause of childhood obesity.
authors: Division of Pediatrics and Perinatology, Tottori University, Yonago, Japan.
authors: Tomoe
authors: T
authors: Kinoshita
authors: Keiichi
authors: K
authors: Hanaki
authors: Jun-Ichi
authors: J
authors: Nagaishi
authors: Yuki
authors: Y
authors: Kawashima
authors: Kaori
authors: K
authors: Adachi
authors: Eiji
authors: E
authors: Nanba
authors: Susumu
authors: S
authors: Kanzaki
mesh_terms: D002648:Child; D005260:Female; D006128:Growth / Q000235:genetics; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D009765:Obesity / Q000453:epidemiology / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D044105:Receptor, Melanocortin, Type 4 / Q000235:genetics*; D022702:Receptors, Adrenergic, beta-3 / Q000235:genetics*; D018709:Statistics, Nonparametric; D015430:Weight Gain / Q000235:genetics
chemical_list: D044105:Receptor, Melanocortin, Type 4; D022702:Receptors, Adrenergic, beta-3