title: MRI Phenotyping of COL9A2/Trp2 and COL9A3/Trp3 Alleles in Lumbar Disc Disease: A Case-control Study in South-Western Iranian Population Reveals a Significant Trp3-Disease Association in Males.
abstract: METHODS
  A case-control study of the Trp2/3 alleles of COL9A2/3 genes and their correlation with occurrence of Lumbar disc disease (DDD) as phenotyped by magnetic resonance imaging.
  
  
  OBJECTIVE
  To establish a better understanding of relationship between presence of said alleles and occurrence of DDD in South-Western Iranian population.
  
  
  BACKGROUND
  A number of genetic predisposing factors have been identified in elevating the risk of developing DDD. Specifically, the Trp2 and Trp3 alleles of COL9A2 and COL9A3 genes have been suggested as DDD risk variants.
  
  
  METHODS
  A total of 108 patients (mean age = 41±11.8 yrs, range = 20-66 yrs) with 57 controls (mean age = 35±10.0 yrs, range = 20-58 yrs) participated in the study. The frequency of G/A polymorphism in COL9A2 gene on location 326 on chromosome 1 and G/A/C/ or T polymorphism in 103 location of COL9A3 gene on chromosome 20 was assessed using a PCR short-primer technique. Outcome measure was defined as presence of DDD on MRI. Odds ratios (OR) and 95% confidence intervals (CI) were used to assess the likelihood of DDD given occurrence of Trp2(3).
  
  
  RESULTS
  Each allele was present in both patients and controls. The Trp2 allele was positive in 28.5% of individuals (31.5% of patients; 22.8% of controls), OR 1.55 (0.71-3.56). The Trp3 allele, the frequency was 23.6% in all patients (26.9% patients; 17.5% controls), OR 1.72 (0.73-4.33). We observed a 5.8-fold increase in the odds of DDD in males when the Trp3 allele was present, OR 5.83 (1.09-9.98), P = 0.0273.
  
  
  CONCLUSIONS
  Both Trp2 and Trp3 alleles occurred more frequently compared with other studied ethnicities. The sampled Iranian population exhibited a similar Trp2 frequency to a Southern Chinese population, and Trp3 occurrence to Finnish and Greek population. We found that male patient were much more likely to develop DDD when Trp 3 was present.
  
  
  METHODS
  N/A.
authors: Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.|Department of Radiology, Shiraz University of Medical Sciences, Shiraz, Iran.|Department of Radiology, Brigham and Women's Hospital, Boston, MA.
authors: Mohammad H
authors: MH
authors: Bagheri
authors: Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.|Department of Radiology, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Amir P
authors: AP
authors: Honarpisheh
authors: Hematology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Majid
authors: M
authors: Yavarian
authors: Educational Development Centre, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Zahra
authors: Z
authors: Alavi
authors: Department of Radiology, Brigham and Women's Hospital, Boston, MA.|Harvard Medical School, Boston, MA.
authors: Jenifer
authors: J
authors: Siegelman
authors: Department of Radiology, Brigham and Women's Hospital, Boston, MA.|National Center for Biomedical Computing, Informatics for Integrating Biology and the Bedside i2b2, Boston, MA.
authors: Vladimir I
authors: VI
authors: Valtchinov
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D044466:Asian People; D016022:Case-Control Studies; D024081:Collagen Type IX / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging* / Q000235:genetics*; D007492:Iran; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D012737:Sex Factors; D044465:White People; D055815:Young Adult
chemical_list: C120282:COL9A2 protein, human; C120768:COL9A3 protein, human; D024081:Collagen Type IX