title: Relationship between cytosine-adenine repeat polymorphism of ADAMTS9 gene and clinical and radiologic severity of knee osteoarthritis.
abstract: OBJECTIVE
  The aim of this study is to determine the role of cytosine-adenine (CA) micro-satellite repeat sequence of ADAMTS9 gene on the development and progression of osteoarthritis (OA).
  
  
  METHODS
  A total of 110 participants, including those with primary knee OA and healthy controls were enrolled in the study. Patients were stratified into two groups using the Kellgren-Lawrence staging (K-L staging) as group 1 for controls and mild OA and group 2 for moderate and severe OA. Genetic analyses were performed to determine the CA repeat length in ADAMTS9 gene.
  
  
  RESULTS
  Twenty CA repeats were found to be statistically significant for differentiating groups 1 and 2 (P = 0.020). Age was the most significant risk factor involved, followed by ≥ 20 CA repeats and body mass index (P < 0.05). CA repeat length of ≥ 20 showed a 6.1-fold increase in probability for having OA at stage 3 or 4 compared to those of CA repeat length of < 20 (P = 0.004). In conclusion, the CA repeat length of ≥ 20 has a six-fold increase in probability for having severe OA.
  
  
  CONCLUSIONS
  ADAMTS9 gene CA repeat polymorphism may be used to determine the prognosis for OA radiologic progression. Being the first in the literature reporting the CA repeat in the promotor region of ADAMTS9 gene in patients with OA, our study could be highlighted further in future research with larger sample size.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Division of Rheumatology, Faculty of Medicine, Erciyes University, Kayseri, Turkey.
authors.forename: Kevser
authors.identifier: http://orcid.org/0000-0001-8639-751X
authors.initials: K
authors.lastname: Gok
authors.affiliation: Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Turgut Ozal University, Ankara, Turkey.
authors.forename: Ozlem
authors.initials: O
authors.lastname: Cemeroglu
authors.affiliation: Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Turgut Ozal University, Ankara, Turkey.
authors.forename: Hasim
authors.initials: H
authors.lastname: Cakirbay
authors.affiliation: Department of Medical Genetics, Faculty of Medicine, Turgut Ozal University, Ankara, Turkey.
authors.forename: Esra
authors.initials: E
authors.lastname: Gunduz
authors.affiliation: Department of Medical Genetics, Faculty of Medicine, Turgut Ozal University, Ankara, Turkey.
authors.forename: Muradiye
authors.initials: M
authors.lastname: Acar
authors.affiliation: Department of Medical Genetics, Faculty of Medicine, Turgut Ozal University, Ankara, Turkey.
authors.forename: Elif Nihan
authors.initials: EN
authors.lastname: Cetin
authors.affiliation: Department of Medical Genetics, Faculty of Medicine, Turgut Ozal University, Ankara, Turkey.|Department of Otolaryngology, Faculty of Medicine, Turgut Ozal University, Ankara, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Gunduz
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Turgut Ozal University, Ankara, Turkey.
authors.forename: Kadir
authors.initials: K
authors.lastname: Demircan
mesh_terms: D000071119:ADAMTS9 Protein / Q000235:genetics*; D000225:Adenine; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003596:Cytosine; D018450:Disease Progression; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D016015:Logistic Models; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000201:enzymology / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D011379:Prognosis; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D003596:Cytosine; D000071119:ADAMTS9 Protein; C412869:ADAMTS9 protein, human; D000225:Adenine
keywords: ADAMTS9 gene; cytosine-adenine repeat; osteoarthritis; polymorphism