title: Periostin gene variants are associated with disease course and severity in juvenile idiopathic arthritis.
abstract: OBJECTIVE
  This study aimed to identify polymorphic variants of the Periostin gene associated with disease severity and clinical course in children with juvenile idiopathic arthritis.
  
  
  METHODS
  DNA genotyping of 7 single-nucleotide polymorphisms within the periostin gene was performed in 117 patients and their parents and in 102 control samples. Our patients were divided in the following 4 disease categories: 1) persistent oligoarthritis; 2) extended oligoarthritis; 3) polyarthritis; 4) systemic arthritis. Quantitative association analysis was performed in order to test for association between the 7 genetic variants and 18 selected clinical traits.
  
  
  RESULTS
  A harmful association was observed between the minor allele of rs17197936 and 2 clinical traits, count of joints with active arthritis and count of joints with pain on motion/tenderness, in patients with extended oligoarthritis. Furthermore, the haplotype represented by the minor allele variants of rs3829364, rs6750 and rs9547951 showed an unfavourable association with the above 2 traits plus the following 3 in the whole patient group: juvenile arthritis damage index articular score, childhood health assessment questionnaire score and disease duration.
  
  
  CONCLUSIONS
  These associations suggest that the variants involved can be regarded as genetic factors influencing some phenotypic aspects of juvenile idiopathic arthritis. Genotyping of this gene may represent a useful tool to identify patients who are at greatest risk of experiencing a poorer long-term outcome.
authors.affiliation: Laboratorio di Genetica Molecolare, Istituto Giannina Gaslini, Genova, Italy. angelacovone@ospedale-gaslini.ge.it.
authors.forename: Angela Elvira
authors.initials: AE
authors.lastname: Covone
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Solari
authors.forename: Clara
authors.initials: C
authors.lastname: Malattia
authors.forename: Valentin
authors.initials: V
authors.lastname: Pop
authors.forename: Alberto
authors.initials: A
authors.lastname: Martini
authors.forename: Angelo
authors.initials: A
authors.lastname: Ravelli
authors.forename: Roberto
authors.initials: R
authors.lastname: Ravazzolo
mesh_terms: D001171:Arthritis, Juvenile / Q000175:diagnosis / Q000235:genetics*; D016022:Case-Control Studies; D015815:Cell Adhesion Molecules / Q000235:genetics*; D004185:Disability Evaluation; D018450:Disease Progression; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D011237:Predictive Value of Tests; D040641:Quantitative Trait Loci; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D015815:Cell Adhesion Molecules; C512835:POSTN protein, human