title: The association of the mitochondrial DNA OriB variant (16184-16193 polycytosine tract) with type 2 diabetes in Europid populations.
abstract: OBJECTIVE
  The association between the mitochondrial DNA 16181-16193 polycytosine variant (known as the OriB variant as it maps to the OriB origin of replication) and type 2 diabetes has not been reliably characterised, with studies reporting conflicting results. We report a systematic review of published literature in Europid populations, new data from the Norfolk Diabetes Case-Control Study and a meta-analysis to help quantify this association.
  
  
  METHODS
  We performed a systematic review identifying all the studies of the OriB variant and type 2 diabetes in Europid populations published before January 2013. We typed the OriB variant by pyrosequencing and sequencing in the Norfolk Diabetes Case-Control Study, which comprised 5,574 type 2 diabetes cases and 6,950 population-based controls.
  
  
  RESULTS
  Overall, the meta-analysis included eight published studies plus the current new results, with a total of 11,794 type 2 diabetes cases and 14,465 controls. In the Norfolk Diabetes Case-Control Study, the OR for type 2 diabetes for the OriB variant was 1.09 (95% CI 0.96, 1.24). In a combined analysis, the relative risk for type 2 diabetes for the OriB variant in Europid populations was 1.10 (95% CI 1.01, 1.20; p = 0.03) CONCLUSIONS/INTERPRETATION: Results from this systematic review and meta-analysis suggest that the mitochondrial DNA OriB variant is modestly associated with an increased risk of type 2 diabetes in Europid populations, with an effect size comparable with that of recently identified variants from genome-wide association studies.
authors.affiliation: Medical Research Council Epidemiology Unit, Institute of Metabolic Science, Addenbrooke's Hospital, PO Box 285, Hills Road, Cambridge CB2 0QQ, UK. zheng.ye@mrc-epid.cam.ac.uk
authors.forename: Zheng
authors.initials: Z
authors.lastname: Ye
authors.forename: Christopher
authors.initials: C
authors.lastname: Gillson
authors.forename: Matt
authors.initials: M
authors.lastname: Sims
authors.forename: Kay-Tee
authors.initials: KT
authors.lastname: Khaw
authors.forename: Magdalena
authors.initials: M
authors.lastname: Plotka
authors.forename: Joanna
authors.initials: J
authors.lastname: Poulton
authors.forename: Claudia
authors.initials: C
authors.lastname: Langenberg
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Wareham
mesh_terms: D004272:DNA, Mitochondrial / Q000235:genetics*; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans
chemical_list: D004272:DNA, Mitochondrial