 Jansen's metaphyseal chondrodysplasia

Jansen's metaphyseal chondrodysplasia (JMC) is a disease that results from ligand-independent activation of the type 1 (PTH1R) of the parathyroid hormone receptor, due to one of three reported mutations (activating mutation).JMC is extremely rare, and as of 2007 there are fewer than 20 reported cases worldwide.