The extent of ossification of posterior longitudinal ligament of the spine associated with nucleotide pyrophosphatase gene and leptin receptor gene polymorphisms.
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.
Tahara
Masamichi
M
Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
Aiba
Atsuomi
A
Yamazaki
Masashi
M
Ikeda
Yoshikazu
Y
Goto
Sumio
S
Moriya
Hideshige
H
Okawa
Akihiko
A
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
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