Studies for elucidating the etiology of the ossification of posterior longitudinal ligament of spine

为了确定脊柱后纵韧带骨化的原因和发展过程，我们通过1)家族研究，2)双胞胎研究和3)遗传标记研究来研究其遗传方面和遗传机制。研究结果表明，OPLL在被研究孕妇的子女和兄弟姐妹中的发病率高于一般人群，并且，OPLL一致性在同卵双胞胎中高于异卵双胞胎。从这些观察中，我们得出结论，遗传因素在脊柱外韧带的发生和发展中起主要作用。1)家族研究：利用家族数据编制的OPLL分离比率，确定其与简单隐性遗传和显性遗传假设的潜在一致性，但未得到任何结结性发现。然而，我们已经能够贴切地将OPLL复发风险与多因子遗传假设相关联。2)双胞胎研究：同卵组OPLL一致性比例为3/5，异卵组为0/1。尽管病例数量有限，但我们认为这种差异足以暗示多因子遗传假说是一个真实的命题。3)遗传标记研究：对OPLL患者与东京健康供者在16个遗传标记方面进行了比较研究。对两组数据的分析没有使我们能够确定任何标记物与OPLL的伦理学有显著关系。

In an attempt to determine the causation,and developmental process,of the ossification of posterior longitudinal ligaments (OPLL)of the spine,we inverstigated its hereditary aspects and genetic mechanism by conduction 1)family studies,2)twin studies and 3)studies on genetic markers. Results of the studies indicated that OPLL's ratio of incidence was higher among the children and siblings of the proposituses studied than among the general population and,further,that OPLL concordance was higher among the monozygotic twins than among their dizygotic counterparts. From such observations,we conclude that hereditary factors have a major role toplay in the incidence and development of the OPLL of the spine.1)Family studies:Using segregation ratios of OPLL compiled from familial data,we ascertained the potential conformity with the hypotheses of the simple recessive and dominant inheritance, we could not get any conclusive finding.We have been able,however,to fitly correlate the OPLL recurrence risks identified wuth the hypothesis of the multifactorial inheritance.2)Twin studies:Ratio of OPLL concordance was 3/5 for the monozygotic group and 0/1 for the dizygotic group of twins.Despite the limited number of cases,we considered such a difference enough to imply that the hypothesis of multifactorial inheritance is a veritable proposition.3)Genetic marker studiss:A comparative study was made between the OPLL propositases and healthy donors residing inTokyo in respect with sixteen genetic markers.An analysis of data in the two groups did not enable us to identify any marker as having a significant relationship with the ethiology of OPLL.