New Mouse Model Offers Breakthrough Insights and Therapeutic Hope for Jansen’s Disease

We’re thrilled to feature a groundbreaking study that brings unprecedented clarity to the biological mechanisms underlying Jansen’s metaphyseal chondrodysplasia (JMC), while paving the way toward potential treatments.

In a landmark paper published in PNAS in June 2025, researchers successfully generated a stable mouse model carrying a human PTH1R mutation (T410R) known to cause JMC. Unlike previous models with severe phenotypes, this “humanized” mouse model mirrors critical disease features—such as misshapen bones, disorganized growth plate architecture, and mineral ion imbalances, while allowing normal lifespan and reproduction

Advanced imaging confirmed impaired mineralization and vascularization in growth plates, and key biomarkers such as high serum calcium and suppressed endogenous PTH accurately reflected the human condition. Importantly, early proof-of-concept studies showed that administering a PTH inverse agonist restored mineral balance, confirming the path toward therapeutic intervention.

This model stands as a powerful tool for dissecting the molecular pathways driving JMC and for evaluating the safety and efficacy of new therapies, including inverse agonist ligands.