Jansen's Disease: Bone Abnormalities Beyond Chondrodysplasia

The H223R-PTH1R mutation in patients with JMC leads to bone structural irregularities, hypomineralization, abnormal osteocyte morphology, and altered expression of osteocyte-derived proteins. These findings underscore the multifaceted impact of the mutant PTH1R on bone physiology and focus attention on the osteocyte as a cellular target for therapeutic intervention. Whether normalizing gene expression in osteocytes is possible and can improve bone health in patients with JMC remains to be seen. Assessment of osteocyte morphology and function may provide novel diagnostic endpoints for future clinical trials with JMC therapeutics.