title: The extent of ossification of posterior longitudinal ligament of the spine associated with nucleotide pyrophosphatase gene and leptin receptor gene polymorphisms.
abstract: METHODS
  A case-control study using radiograph findings and the PCR assay with regard to the susceptibility and the severity of ossification of posterior longitudinal ligament of the spine (OPLL).
  
  
  OBJECTIVE
  To analyze whether polymorphisms of the nucleotide pyrophosphatase (NPPS) gene and the leptin receptor gene predispose to an increased frequency and severity of OPLL.
  
  
  BACKGROUND
  The NPPS gene is responsible for ectopic ossification in the ttw mouse, an animal model for OPLL. The Zucker fatty rat, another animal model for OPLL, has a missense mutation in the leptin receptor gene.
  
  
  METHODS
  Analysis of 172 OPLL patients and 93 non-OPLL controls was performed. Radiographs of the cervical, thoracic and lumber spine were analyzed to determine whether OPLL was present and to what degree. Genomic DNA was extracted from all participants. Polymorphisms of the NPPS gene and the leptin receptor gene were analyzed using the PCR assay. The association of the polymorphisms with the development and extent of OPLL were statistically evaluated.
  
  
  RESULTS
  No significant association was found between the polymorphisms and the existence of OPLL in both the NPPS and the leptin receptor genes. However, the IVS20-11delT variant in the NPPS gene and the A861G variant in the leptin receptor gene were more frequent in patients with OPLL in the thoracic spine compared with patients whose OPLL was restricted to the cervical spine.
  
  
  CONCLUSIONS
  The present results suggest that the IVS20-11delT variant of the NPPS gene and the A861G variant of the leptin receptor gene are associated with more extensive OPLL, but not with the frequency with which it occurs.
authors.affiliation: Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Tahara
authors.forename: Atsuomi
authors.initials: A
authors.lastname: Aiba
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Sumio
authors.initials: S
authors.lastname: Goto
authors.forename: Hideshige
authors.initials: H
authors.lastname: Moriya
authors.forename: Akihiko
authors.initials: A
authors.lastname: Okawa
mesh_terms: D000225:Adenine; D016022:Case-Control Studies; D005260:Female; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006147:Guanine; D006801:Humans; D007438:Introns; D017846:Longitudinal Ligaments / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000000981:diagnostic imaging* / Q000235:genetics*; D011110:Polymorphism, Genetic; D011755:Pyrophosphatases / Q000235:genetics*; D011859:Radiography; D011956:Receptors, Cell Surface / Q000235:genetics*; D054411:Receptors, Leptin; D012720:Severity of Illness Index; D013131:Spine / Q000000981:diagnostic imaging; D013941:Thymine
chemical_list: C515448:LEPR protein, human; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; C515447:leptin receptor, mouse; D006147:Guanine; D011755:Pyrophosphatases; C021899:nucleotide pyrophosphatase; D000225:Adenine; D013941:Thymine