Noggin is a glycoprotein predominantly expressed by the dorsal mesoderm during embryogenesis and is secreted as a covalently linked homodimer. Noggin is essential for cartilage morphogenesis and joint formation. It is an inhibitor of bone morphogenic proteins (BMP) signaling which is required for growth and patterning of the neural tube and somite. Defects in Noggin are a cause of symphalangism proximal syndrome (SYM1), of multiple synostoses syndrome 1 (SYNS1), of the tarsal-carpal coalition syndrome (TCC), of stapes ankylosis with broad thumb and toes, and of brachydactyly type B2 (BDB2).
