title: IRAK1 variant is protective for orthodontic-induced external apical root resorption.
abstract: OBJECTIVE
  Interleukin-1 beta (IL1B) pathway is a key player in orthodontic-induced external apical root resorption (EARR). The aim of this work was to identify the genes related to the IL1 pathway as possible candidate genes for EARR, which might be included in an integrative predictive model of this complex phenotype.
  
  
  METHODS
  Using a stepwise multiple linear regression model, 195 patients who had undergone orthodontic treatment were assessed for clinical and genetic factors associated with %EARRmax (maximum %EARR value obtained for each patient). The four maxillary incisors and the two maxillary canines were assessed. Three functional single nucleotide polymorphisms (SNPs) were genotyped: rs1143634 in IL1B gene, rs315952 in IL1RN gene, and rs1059703 in X-linked IRAK1 gene.
  
  
  RESULTS
  The model showed that four of the nine clinical variables and one SNP explained 30% of the %EARRmax variability. The most significant unique contributions to the model were gender (P = 0.001), treatment duration (P < 0.001), premolar extractions (P = 0.003), Hyrax appliance (P < 0.001), and homozygosity/hemizygosity for variant C from IRAK1 gene (P = 0.018), which proved to be a protective factor.
  
  
  CONCLUSIONS
  IRAK1 polymorphism is proposed as a protective variant for EARR.
authors.affiliation: Department of Orthodontics, Dentistry Area, Faculty of Medicine, University of Coimbra, Coimbra, Portugal. soalves1@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Pereira
authors.affiliation: Medical Genetics Department, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Nogueira
authors.affiliation: Department of Physics and Mathematics, Polytechnic Institute of Coimbra (IPC), Coimbra, Portugal.
authors.forename: F
authors.initials: F
authors.lastname: Canova
authors.affiliation: Computer Graphics Center, University of Minho, Guimarães, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Lopez
authors.affiliation: Medical Genetics Department, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.|CIMAGO (Center of Investigation on Environmental, Genetics and Oncobiology), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
authors.forename: H C
authors.initials: HC
authors.lastname: Silva
mesh_terms: D000293:Adolescent; D005260:Female; D014644:Genetic Variation; D006801:Humans; D053592:Interleukin-1 Receptor-Associated Kinases / Q000235:genetics*; D053583:Interleukin-1beta / Q000378:metabolism*; D008297:Male; D009970:Orthodontics; D020641:Polymorphism, Single Nucleotide; D012391:Root Resorption / Q000235:genetics*
chemical_list: D053583:Interleukin-1beta; C507768:IRAK1 protein, human; D053592:Interleukin-1 Receptor-Associated Kinases
keywords: IRAK1 gene; external apical root resorption; gene polymorphism; orthodontics