title: Multiple superoxide dismutase 1/splicing factor serine alanine 15 variants are associated with the development and progression of diabetic nephropathy: the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Genetics study.
abstract: BACKGROUND
  Despite familial clustering of nephropathy and retinopathy severity in type 1 diabetes, few gene variants have been consistently associated with these outcomes.
  
  
  METHODS
  We performed an individual-based genetic association study with time to renal and retinal outcomes in 1,362 white probands with type 1 diabetes from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study. Specifically, we genotyped 1,411 SNPs that capture common variations in 212 candidate genes for long-term complications and analyzed them for association with the time from DCCT baseline to event for renal and retinal outcomes using multivariate Cox proportion hazards models. To address multiple testing and assist interpretation of the results, false discovery rate q values were calculated separately for each outcome.
  
  
  RESULTS
  We observed association between rs17880135 in the 3' region of superoxide dismutase 1 (SOD1) and the incidence of both severe nephropathy (hazard ratio [HR] 2.62 [95% CI 1.64-4.18], P = 5.6 x 10(-5), q = 0.06) and persistent microalbuminuria (1.82 [1.29-2.57], P = 6.4 x 10(-4), q = 0.46). Sequencing and fine-mapping identified additional SOD1 variants, including rs202446, rs9974610, and rs204732, which were also associated (P < 10(-3)) with persistent microalbuminuria, whereas rs17880135 and rs17881180 were similarly associated with the development of severe nephropathy. Attempts to replicate the findings in three cross-sectional case-control studies produced equivocal results. We observed no striking differences between risk genotypes in serum SOD activity, serum SOD1 mass, or SOD1 mRNA expression in lymphoblastoid cell lines.
  
  
  CONCLUSIONS
  Multiple variations in SOD1 are significantly associated with persistent microalbuminuria and severe nephropathy in the DCCT/EDIC study.
authors.affiliation: Program in Genetics and Genome Biology, The Hospital for Sick Children, TMDT Building East Tower, Rm. 15-707, 101 College St., Toronto, Ontario, Canada.
authors.forename: Hussam
authors.initials: H
authors.lastname: Al-Kateb
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Boright
authors.forename: Lucia
authors.initials: L
authors.lastname: Mirea
authors.forename: Xinlei
authors.initials: X
authors.lastname: Xie
authors.forename: Rinku
authors.initials: R
authors.lastname: Sutradhar
authors.forename: Alireza
authors.initials: A
authors.lastname: Mowjoodi
authors.forename: Bhupinder
authors.initials: B
authors.lastname: Bharaj
authors.forename: Michelle
authors.initials: M
authors.lastname: Liu
authors.forename: Jean M
authors.initials: JM
authors.lastname: Bucksa
authors.forename: Valerie L
authors.initials: VL
authors.lastname: Arends
authors.forename: Michael W
authors.initials: MW
authors.lastname: Steffes
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Cleary
authors.forename: Wanjie
authors.initials: W
authors.lastname: Sun
authors.forename: John M
authors.initials: JM
authors.lastname: Lachin
authors.forename: Paul S
authors.initials: PS
authors.lastname: Thorner
authors.forename: Michael
authors.initials: M
authors.lastname: Ho
authors.forename: Amy Jayne
authors.initials: AJ
authors.lastname: McKnight
authors.forename: A Peter
authors.initials: AP
authors.lastname: Maxwell
authors.forename: David A
authors.initials: DA
authors.lastname: Savage
authors.forename: Kenneth K
authors.initials: KK
authors.lastname: Kidd
authors.forename: Judith R
authors.initials: JR
authors.lastname: Kidd
authors.forename: William C
authors.initials: WC
authors.lastname: Speed
authors.forename: Trevor J
authors.initials: TJ
authors.lastname: Orchard
authors.forename: Rachel G
authors.initials: RG
authors.lastname: Miller
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.forename: Shelley B
authors.initials: SB
authors.lastname: Bull
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Paterson
mesh_terms: D000409:Alanine; D000419:Albuminuria / Q000235:genetics; D019943:Amino Acid Substitution; D003928:Diabetic Nephropathies / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics*; D003930:Diabetic Retinopathy / Q000235:genetics; D018450:Disease Progression; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D009687:Nuclear Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D016601:RNA-Binding Proteins / Q000235:genetics*; D012694:Serine; D000068103:Serine-Arginine Splicing Factors; D013482:Superoxide Dismutase / Q000235:genetics*; D000072105:Superoxide Dismutase-1; D016896:Treatment Outcome
chemical_list: D007004:Hypoglycemic Agents; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C000606290:SOD1 protein, human; D000068103:Serine-Arginine Splicing Factors; D012694:Serine; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D000409:Alanine