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

为明确脊柱后纵韧带骨化症（OPLL）的病因和发生过程，我们通过家系研究、双生子研究和遗传标记研究，探讨了OPLL的遗传学特点和遗传机制。研究结果表明，OPLL的发病率比研究的先证者的子女和兄弟姐妹中高于一般人群，而且，OPLL的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OPLL的发生和发展中起主要作用。1）家系研究：使用从家族资料中收集的OPLL分离比，我们确定了与简单隐性和显性遗传假设的潜在一致性，我们不能得到任何结论性的发现。但是，我们能够将所确定的OPLL复发风险与多因素遗传假设相关联。2）双生子研究：双胞胎单卵组OPLL符合率为3/5，双卵组为0/1。我们认为这种差异足以暗示多因子遗传的假设是一个名副其实的命题。3）遗传标记研究：在OPLL前体酶和居住在东京的健康供体之间进行了关于16个遗传标记的比较研究。与OPLL的伦理学关系。

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.