Analysis of Vitamin D Receptor Gene Polymorphism in Patients with Ossification of Posterior Longitudinal of the Cervical Spine

Several studies have reported the increase of bone density in the patients suffering from ossification of posterior longitudinal ligament of the cervical spine (OPLL). In 1994, Morrison et al. stuidied the correlation between the bone density and gene polymorphism (BB, Bb, bb) digested with Bsm1 restriction enzyme and reported a significant decrease of the maximum bone density in order of BB, Bb and bb types. So we performed these experiments in order to study the receptor gene polymorphism in patients with OPLL. The subjects of the present study included 27 patients with OPLL of the cervical spine and 56 healthy volunteers. Our results of healthy volunteers, unlike theirs that showed the Caucasian patterm, demonstrated the dominance of bb type and the extremely limited unmber of BB type. this finding agreed with the results of other studies perfomed in some other institutes in Japan. In the OPLL group, most of the patients, except one who belonged to Bb type, werw classified into bb type. It is quite natural that many OPLL patients who have higher bone density than healthy volunteers are classified into bb type of the gene with higher bone density. However, we have to admit the fact that bb typoe is frequecy detected in Japanese. Therefore we should not regard the high frequency of bb type as the causative factor of OPLL but should regard BB type with lower bone density as inhibitory factor for the development of OPLL. The racial background that the incidence of OPLL is high in Asiancountries is probably related to the recoal difference in the polymorphism of the vitamin D receptor gene.

ビタミンDリセプター遺伝子多型

脊柱靭帯骨化症