Wada Keiji, Kanaya Koichi, Murata Yasuaki, Kato Yoshiharu
Department of Orthopaedics, Tokyo Women's Medical University, Tokyo, Japan.
Asian Spine J. 2015 Apr;9(2):286-9. doi: 10.4184/asj.2015.9.2.286. Epub 2015 Apr 15.
Pycnodysostosis is an autosomal recessive disorder characterized by osteosclerosis, small stature, acro-osteolysis of the distal phalanges, loss of the mandibular angle, separated cranial sutures with open fontanels, and frequent fractures. One identified cause of the disease is reduced activity of the cysteine protease cathepsin K. A 48-year-old woman with a history of frequent fractures presented with a severe gait disturbance. Radiography, computed tomography, magnetic resonance imaging, and gene analysis were performed. Physical examination revealed open fontanels, and radiographs showed increased bone density. DNA sequence analysis revealed a deletion mutation of the cathepsin K gene. We diagnosed pycnodysostosis based on these findings. The magnetic resonance and computed tomography images demonstrated multilevel spinal canal stenosis due to ossification of the yellow ligament. We performed a laminectomy, and the patient's neurological signs and symptoms improved. To our knowledge, this is the first case of pycnodysostosis with ossification of the yellow ligament.
致密性骨发育不全是一种常染色体隐性疾病，其特征为骨质硬化、身材矮小、远端指骨肢端骨质溶解、下颌角消失、颅缝分离伴囟门开放以及频繁骨折。已确定该疾病的一个病因是半胱氨酸蛋白酶组织蛋白酶K的活性降低。一名有频繁骨折病史的48岁女性出现严重步态障碍。进行了X线摄影、计算机断层扫描、磁共振成像和基因分析。体格检查发现囟门开放，X线片显示骨密度增加。DNA序列分析显示组织蛋白酶K基因存在缺失突变。基于这些发现，我们诊断为致密性骨发育不全。磁共振成像和计算机断层扫描图像显示由于黄韧带骨化导致多节段椎管狭窄。我们实施了椎板切除术，患者的神经体征和症状得到改善。据我们所知，这是首例伴有黄韧带骨化的致密性骨发育不全病例。
