title: Association between rs12970134 Near MC4R and adiposity indexes in a homogenous population of Caucasian schoolchildren.
abstract: BACKGROUND
  To assess whether previously identified obesity-susceptibility loci were associated with overweight/obesity risk in a homogeneous population of Caucasian schoolchildren and whether these associations varied with age.
  
  
  METHODS
  Seven hundred and forty-five schoolchildren (353 boys, mean age: 8.3 ± 1.4 years) underwent anthropometric assessments. A saliva sample was collected for DNA extraction and assessment of 19 single-nucleotide polymorphisms previously associated with obesity.
  
  
  RESULTS
  Only the rs12970134 in the MC4R gene was significantly associated with overweight/obesity risk, with a higher frequency of the AA risk genotype in children with a BMI >85th (8.3%) than in those with a BMI <85th percentile (3.0%), p = 0.001; odds ratio (95% CI) of 1.544 (1.192-1.998), p = 0.001, after adjusting for age, sex and pubertal stage. BMI standard deviation scores (SDS) and waist-to-height ratio (W/Hr) progressively increased across the rs12970134 genotypes (GG vs. AG vs. AA): BMI SDS, p = 0.004; W/Hr, p = 0.009. When dividing the study population into two groups based on the median age of participants (8.3 years), the differences in BMI SDS and W/Hr across the MC4R genotypes persisted only in children older than 8.3 years.
  
  
  CONCLUSIONS
  In a population of Caucasian schoolchildren, the rs12970134 MC4R variant was significantly associated with excess body weight, particularly in children older than 8 years of age.
authors.affiliation: Department of Paediatrics, University of Chieti, Chieti, Italy.
authors.forename: M Loredana
authors.initials: ML
authors.lastname: Marcovecchio
authors.forename: Rita
authors.initials: R
authors.lastname: Capanna
authors.forename: Ebe
authors.initials: E
authors.lastname: D'Adamo
authors.forename: Sandra
authors.initials: S
authors.lastname: Mammarella
authors.forename: Laura
authors.initials: L
authors.lastname: De Lellis
authors.forename: Francesco
authors.initials: F
authors.lastname: Chiarelli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cama
authors.forename: Angelika
authors.initials: A
authors.lastname: Mohn
mesh_terms: D050154:Adiposity / Q000235:genetics*; D001794:Blood Pressure; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D009765:Obesity / Q000453:epidemiology; D063766:Pediatric Obesity / Q000453:epidemiology / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D044105:Receptor, Melanocortin, Type 4 / Q000235:genetics*; D018570:Risk Assessment; D044465:White People
chemical_list: C470072:MC4R protein, human; D044105:Receptor, Melanocortin, Type 4