后纵韧带骨化症（OPLL）是脊柱后纵韧带异位骨化压迫脊髓导致的脊髓病。颈椎多见，发病于胸椎者少但严重。该疾病具有明显种族好发特性，几乎仅见于日本、韩国及中国北方汉族人群。既往研究提示多个成骨相关基因的多态性与该病的颈椎病变发生及发展相关，针对胸椎OPLL的基因多态性研究尚缺乏。我们前期研究发现OPLL患者的自然病程差异极大，部分患者病情进展缓慢，而部分呈快速进展。本研究将在中国北方汉族人群胸椎OPLL患者中，对筛选出的成骨相关基因启动子、外显子和内含子进行测序，寻找潜在相关多态性位点，分析其与OPLL的发生、累及范围（严重程度）、病情进展速度的相关性。采用重组质粒转染、电泳移动漂移及染色质免疫沉淀实验对高度相关的启动子区多态性进行功能验证，并从多基因共转染和mRNA选择性剪切方面对外显子及内含子区多态性进行功能验证，探索疾病的发病机制，寻找评估疾病进展倾向的指标。

Ossification of the posterior longitudinal ligament (OPLL) is the myelopathy caused by heterotopic ossification of the posterior longitudinal ligament. The most common site of OPLL is the cervical spine while thoracic OPLL(T-OPLL) is rare but more severe. The disease has obvious characteristics of ethnic predilection, almost only found in Japanese, Korean and Han people of Northern China. Previous studies have suggested a number of osteogenic gene polymorphisms associated with the occurrence and development of cervical OPLL, but genetic studies for thoracic OPLL are rare. Our previous studies have found significant differences in the natural history of patients with T-OPLL; slow disease progression was seen in some patients, while rapid progression in other patients was noted. This study is based on the Han people of Northern China with T-OPLL, in which their osteogenesis-related genes (including the promoter, exons and introns) will be screened out and tested for potentially relevant genetic polymorphism, which will be analysed for its association with the occurrence, range(disease severity) and disease progression of T-OPLL. By using recombinant plasmid transfection, electrophoretic mobility shift and chromatin immunoprecipitation to take functional verification of the highly relevant promoter region gene polymorphism and using multi-gene co-transfection and mRNA splicing to take functional verification of exon and intron gene polymorphism, we hope to explore the pathogenesis of this disease and search for potential indicators that can help assess disease progression of OPLL.