Pycnodysostosis (PYCD) is a rare recessive inherited skeletal disease, characterized by short stature, brittle bones, and recurrent fractures, caused by variants in the Cathepsin K encoding gene that leads to impaired osteoclast-mediated bone resorption.
Mutation in CTSK gene is associated with loss of collagenolytic activity of CTSK leading to an autosomal recessive bone disorder called pycnodysostosis.
Our findings expand the mutational spectrum of CTSK gene and emphasize the importance of full clinical examination of all body systems including thorough orodental evaluation in patients with pycnodysostosis.
In this review, we highlight the relationship between CTSK and oral and maxillofacial disorders on the following three aspects: oral and maxillofacial abnormities in patients with pycnodysostosis caused by CTSK mutations, oral and maxillofacial abnormities in Ctsk(-/-) mice, and the role of CTSK in oral and maxillofacial diseases, including periodontitis, peri-implantitis, tooth movement, oral and maxillofacial tumor, root resorption, and periapical disease.
Patients with pycnodysostosis have been reported to present specific dental abnormalities; however, whether these dental abnormalities are related to dysfunctional CTSK has never been reported.
Here we investigated the histologic changes of cementum and alveolar bone in a pycnodysostosis patient, caused by novel compound heterozygous mutations in the CTSK gene (c.87 G>A p.W29X and c.848 A>G p.Y283C).
Up to date, 34 different CTSK mutations have been identified in patients with Pyknodysostosis; however, only one mutation was previously identified in a Chinese patient.