DNA analysis by pulsed field gel electrophoresis for ossification of the posterior longitudinal ligament.

我们试图通过对该病患者家庭的DNA分析来确定引起OPLL的基因。从10个家族共40名成员中收集淋巴细胞进行后续遗传分析。x线检查发现，与患者具有相同HLA单倍型的家庭成员后纵韧带骨化的发生率较高。这一发现表明，一些与HLA单倍型相关的遗传因素与OPLL的发病有关。我们试图通过在每个患者的家庭成员中搜索限制性内切酶片段的多态性来确认该基因的存在，使用大型DNA电泳仪。该分析显示，与患者具有相同HLA单倍型的兄弟姐妹通常在6号染色体上表现出2.7 Kb DNA片段的多态性。我们比较了OPLL患者与40名健康志愿者6号染色体2.7 KB DNA片段的多态性。然而，这一比较并没有解决2.7 Kb DNA片段多态性是否为OPLL患者特异性的问题。我们还分析了碱性磷酸酶（ALP）、骨形态发生蛋白(BMP)-2、胶原α -2和组织坏死因子(TNF)- α的遗传多态性。这表明胶原α -2基因多态性的发生率在OPLL组和健康对照组之间有显著差异。胶原α -2基因多态性可能与OPLL的发病有关。本研究是首次对OPLL进行DNA分析。我们认为这项研究是利用分子生物学方法研究OPLL病因学的开创性工作。

We attempted to identify the genes responsible for OPLL by means of DNA analysis of the families of patients with this disease. Lymphocytes were collected from a total of 40 members of 10 families for subsequent genetic analysis. Family members who shared a common HLA haplotype with the patient were found to have a high incidence of ossification of the posterior longitudinal ligament by X-ray examination. This finding suggests that some genetic factors, linked to HLA haplotypes, are involved in the onset of OPLL.We attempted to confirm the presence of this gene by searching for polymorphism of restriction fragments in the members of each patient's family, using a large DNA electrophoresis apparatus. This analysis revealed that the siblings who shared a common HLA haplotype with the patient often showed polymorphism of the 2.7 Kb DNA fragment on chromosome 6. We compared polymorphism of the 2.7 KB DNA fragmetn on chromosome 6 between patinets with OPLL and 40 healthy volunteers. This comparison, however, did not resolve the question of whether or not polymorphism of the 2.7 Kb DNA fragment is specific to OPLL patients.We also analyzed the genetic polymorphism of alkaline phosphatase (ALP), bone morphogenic protein (BMP)-2, collagen alpha-2 and tissue necrosing factor (TNF)-alpha. This revealed that the incidence of polymorphism of the gene of collagen alpha-2 differs significantly between the OPLL group and the healthy controls. It is possible that polymorphism of collagen alpha-2 gene is rosponsible for the onset of OPLL.The present stufy was the first DNA analysis of OPLL.We believe this study has served as pioneering work in the study of the etiology of OPLL,using the methods of molecular biology.