title: The mtDNA 15497 G/A polymorphism in cytochrome b in severe obese subjects from Southern Italy.
abstract: OBJECTIVE
  A large number of mitochondrial DNA (mtDNA) mutations have been implicated in degenerative diseases and aging. The aim of this study was to evaluate whether the 15497 G/A mtDNA polymorphism (G251S) in the cytochrome b subunit of respiratory complex III, which has been associated with obesity-related variables and lipid metabolism in a Japanese population, is associated with severe obesity also in adult Caucasians from southern Italy.
  
  
  RESULTS
  Unrelated severely obese patients (n = 317; BMI > 40kg/m2) and controls (n = 217; BMI < 25kg/m2) from Southern Italy were genotyped by allelic discrimination TaqMan assay for the 15497 G/A mtDNA polymorphism. In obese patients fasting serum total cholesterol, triglycerides, HDL-cholesterol and glucose were measured enzymatically and sitting blood pressure and heart rate were also collected. Mean levels of total cholesterol, triglycerides and glucose were below the upper reference limit for healthy subjects. Female obese subjects showed lower levels of blood pressure and heart rate and higher levels of HDL cholesterol than male obese patients (P < 0.001). All the control subjects and 315/317 severely obese patients were homozygous for the G allele (wild type), whereas only 2/317, were females homozygous for the A allele.
  
  
  CONCLUSIONS
  The mtDNA 15497 G/A polymorphism in cytochrome b was present in 0.6% obese subjects, two females whose lipid parameters and BMI were similar to those of the overall group. Therefore, this mutation may appear to contribute in rare instances to severe obesity but does not explain the majority of cases in our population. A more extensive genetic haplogroup characterization is required to identify associations to obesity in Caucasians.
authors.affiliation: Department of Biochemistry and Medical Biotechnology, University Naples Federico II, Via Pansini 5, 80131 Naples, Italy.
authors.forename: Rosario
authors.initials: R
authors.lastname: Liguori
authors.forename: Cristina
authors.initials: C
authors.lastname: Mazzaccara
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Pasanisi
authors.forename: Pasqualina
authors.initials: P
authors.lastname: Buono
authors.forename: Giovannangelo
authors.initials: G
authors.lastname: Oriani
authors.forename: Carmine
authors.initials: C
authors.lastname: Finelli
authors.forename: Franco
authors.initials: F
authors.lastname: Contaldo
authors.forename: Lucia
authors.initials: L
authors.lastname: Sacchetti
mesh_terms: D000328:Adult; D045303:Cytochromes b / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D014450:Electron Transport Complex III; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D009765:Obesity / Q000208:ethnology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D044465:White People / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D045303:Cytochromes b; D014450:Electron Transport Complex III