Pycnodysostosis

Pycnodysostosis is a lysosomal storage disease of the bone caused by a mutation in the gene that codes for the enzyme cathepsin K. The name comes from the Greek puknos, meaning dense, together with the prefix dys-, meaning defective, and the suffix -ostosis, meaning a condition of the bone, and so describes a bone condition marked by dense but defective bone. The disorder is also abbreviated PKND and PYCD. The short source lead supports only these points, so the account here is intentionally brief.