title: COL6A1 polymorphisms associated with ossification of the ligamentum flavum and ossification of the posterior longitudinal ligament.
abstract: METHODS
  A case-control association study was conducted to investigate the genetic etiology for ossification of the ligamentum flavum (OLF) and ossification of the posterior longitudinal ligament of the spine (OPLL).
  
  
  OBJECTIVE
  To determine whether COL6A1 polymorphisms are associated with susceptibility to OLF and OPLL in Chinese Han population.
  
  
  BACKGROUND
  The COL6A1 has been identified as a susceptibility gene for OPLL in Japanese. The susceptibility gene for OPLL may be different among various populations, so we investigated whether COL6A1 polymorphisms are also associated with OPLL in Chinese Han population. OLF and OPLL are similar in epidemiology, etiology, and pathology, and common coexist. Hereditary factors may be implicated in OLF and COL6A1 may be a potential susceptibility gene for OLF, so we investigated the relations between COL6A1 polymorphisms and OLF.
  
  
  METHODS
  Four known single nucleotide polymorphisms (SNPs) of COL6A1 were genotyped among 338 Chinese Han subjects by high throughput GenomeLab SNPstream genotyping system. Allele frequency and genotype distribution of each polymorphism were compared using a contingency chi2 test between 183 cases (90 OPLL, 61 OLF, and 32 OPLL coexisting with OLF) and 155 controls.
  
  
  RESULTS
  Among 4 studied SNPs, allele frequency of promoter (-572T) SNP demonstrated the most significant difference not only between OPLL cases and controls (P = 2.65E-4), but also between OLF cases and controls (P =7.38E-4). Moreover, the overall frequency of haplotypes constructed from promoter (-572), intron 32 (-29), and intron 33 (+20) SNPs showed significant difference not only between the patients with OPLL and controls, but also between the patients with OLF and controls (P = 5.86E-3, P = 1.5E-8, respectively).
  
  
  CONCLUSIONS
  This is the first report on SNPs of COL6A1 in OLF that suggests polymorphisms may be a risk factor for OLF. Our findings indicate that COL6A1 may be a common susceptibility gene for OLF and OPLL in Chinese Han population.
authors.affiliation: Department of Orthopaedic Surgery, Peking University Third Hospital, Beijing, China.
authors.forename: Qingquan
authors.initials: Q
authors.lastname: Kong
authors.forename: Xi
authors.initials: X
authors.lastname: Ma
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Zhaoqing
authors.initials: Z
authors.lastname: Guo
authors.forename: Qiang
authors.initials: Q
authors.lastname: Qi
authors.forename: Weishi
authors.initials: W
authors.lastname: Li
authors.forename: Haifeng
authors.initials: H
authors.lastname: Yuan
authors.forename: Zili
authors.initials: Z
authors.lastname: Wang
authors.forename: Zhongqiang
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000368:Aged; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D002681:China; D024142:Collagen Type VI / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D007438:Introns; D017843:Ligamentum Flavum / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D017887:Ossification of Posterior Longitudinal Ligament / Q000235:genetics* / Q000473:pathology; D009999:Ossification, Heterotopic / Q000235:genetics* / Q000473:pathology; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D024142:Collagen Type VI