title: Association of VKORC1-1639G>A polymorphism with susceptibility to ossification of the posterior longitudinal ligament of the spine: a Korean study.
abstract: BACKGROUND
  Abnormalities of bone metabolism may be involved in the pathogenesis of ossification of the posterior longitudinal ligament (OPLL) of the spine. Besides its hemostatic effect, vitamin K epoxide reductase complex subunit 1 (VKORC1) plays a pivotal role in bone mineralization. The aim of this study is to investigate whether single nucleotide polymorphisms (SNPs) of the VKORC1 gene are associated with the occurrence of OPLL in a Korean population.
  
  
  METHODS
  A total of 98 patients with OPLL and 200 controls were genotyped for the VKORC1-1639G>A SNP (rs9923231) by polymerase chain reaction and restriction fragment length polymorphism analysis. All the patients (n = 98) in this study underwent surgery (60, posterior-only approach; 36, anterior-only approach; 2, combined anterior and posterior approach) during their admission. We analyzed this association separately according to the gender and OPLL subgroup: OPLL continuous group (continuous type plus mixed type) and OPLL segmental group (segmental and localized type).
  
  
  RESULTS
  We found that the genotype VKORC1-1639G>A frequency was significantly associated with the occurrence of the OPLL in the female group (adjusted odds ratio = 5.22, 95 % confidence interval: 1.675 to 16.269, p = 0.004). However, there was no overall association between the OPLL susceptibility and VKORC1-1639G>A polymorphism. A subgroup analysis did not show any significant correlation between VKORC1-1639G>A polymorphism and subgroup of OPLL either.
  
  
  CONCLUSIONS
  Our results suggest that the VKORC1-1639G>A SNP may increase susceptibility to OPLL in women. However, there was only a statistical association in the female group despite a number of stratified analyses. Therefore, the findings should be interpreted with caution, and further genetic study is needed to improve our understanding of the role of VKORC1 polymorphisms in determining the risk of OPLL occurrence.
authors.affiliation: Department of Neurosurgery, The Spine and Spinal Cord Institute, Yonsei University College of Medicine, 712, Eonjuro, Gangnam-gu, Seoul, 135-720, South Korea.
authors.forename: Dong-Kyu
authors.initials: DK
authors.lastname: Chin
authors.forename: In-Bo
authors.initials: IB
authors.lastname: Han
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Ropper
authors.forename: Young-Joo
authors.initials: YJ
authors.lastname: Jeon
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Kim
authors.forename: Young-Sung
authors.initials: YS
authors.lastname: Kim
authors.forename: Youngseok
authors.initials: Y
authors.lastname: Park
authors.forename: Yang D
authors.initials: YD
authors.lastname: Teng
authors.forename: Nam-Keun
authors.initials: NK
authors.lastname: Kim
authors.forename: Sung-Uk
authors.initials: SU
authors.lastname: Kuh
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000209:etiology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012737:Sex Factors; D064417:Vitamin K Epoxide Reductases / Q000235:genetics*
chemical_list: C578523:VKORC1 protein, human; D064417:Vitamin K Epoxide Reductases