Unidade de Genética, Instituto da Criança, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Am J Med Genet A. 2010 Oct;152A(10):2599-603. doi: 10.1002/ajmg.a.33609.
Pycnodysostosis is a rare autosomal recessive skeletal dysplasia caused by the absence of active cathepsin K, which is a lysosomal cysteine protease that plays a role in degrading the organic matrix of bones, acting in bone resorption and bone remodeling. The disease is primarily characterized by osteosclerosis, bone fragility, short stature, acro-osteolysis, and delayed closure of the cranial sutures. A differing feature, cranial synostosis, has occasionally been described in this disorder. We reviewed six unrelated patients with pycnodysostosis (mean age of 10 years and 4 months) in order to evaluate the presence of craniosynostosis. In addition to the typical findings of the condition, they all presented premature fusion of the coronal suture. Although none of them showed signs of cranial hypertension, one patient had had the craniosynostosis surgically corrected previously. These data suggest that the cranial sutures in pycnodysostosis can display contradictory features: wide cranial sutures, which are commonly described, and craniosynostosis. The clinical impact of this latter finding still remains to be elucidated. Further studies are necessary to address more precisely the role of cathepsin K in suture patency.
骨化不全症是一种罕见的常染色体隐性骨骼发育不良，由组织蛋白酶 K 的缺乏引起，该酶是一种溶酶体半胱氨酸蛋白酶，在降解骨骼的有机基质方面发挥作用，参与骨吸收和骨重塑。该疾病的主要特征是骨硬化、骨骼脆弱、身材矮小、肢端骨溶解和颅缝闭合延迟。颅缝早闭是该病的一个不同特征，偶尔也有描述。我们回顾了 6 例无关联的骨化不全症患者（平均年龄为 10 岁零 4 个月），以评估颅缝早闭的存在。除了该疾病的典型表现外，他们都表现出冠状缝过早融合。尽管他们都没有颅高压的迹象，但有 1 名患者曾接受过颅缝早闭的手术矫正。这些数据表明，骨化不全症的颅缝可能表现出相互矛盾的特征：常见的描述是宽颅缝，以及颅缝早闭。后者的临床意义仍有待阐明。需要进一步的研究来更准确地阐明组织蛋白酶 K 在颅缝开放中的作用。
