What is Pycnodysostosis

Pycnodysostosis is a rare genetic disorder characterized by abnormal bone development. It is also known as Toulouse-Lautrec syndrome, as the famous artist Henri de Toulouse-Lautrec is believed to have had this condition.

Individuals with Pycnodysostosis have a mutation in the CTSK gene, which affects the production of an enzyme called cathepsin K. This enzyme is responsible for breaking down and remodeling bone tissue. The mutation leads to reduced activity of cathepsin K, resulting in abnormal bone growth and remodeling.

Common features of Pycnodysostosis include short stature, brittle bones, and abnormal craniofacial features such as a small jaw, dental abnormalities, and a prominent forehead. Individuals with this condition may also experience delayed closure of the fontanelles (soft spots on the skull) and narrowing of the airways.

Diagnosis of Pycnodysostosis is typically based on clinical features, genetic testing, and imaging studies. While there is no cure for this condition, treatment focuses on managing symptoms and preventing complications. This may involve orthopedic interventions to address bone abnormalities, dental care to manage dental issues, and regular monitoring for potential complications.