Mondo Description Any proximal symphalangism in which the cause of the disease is a mutation in the GDF5 gene.

Uniprot Description A disease characterized by the hereditary absence of the proximal interphalangeal joints. Distal interphalangeal joints are less frequently involved and metacarpophalangeal joints are rarely affected whereas carpal bone malformation and fusion are common. In the lower extremities, tarsal bone coalition is common. Conductive hearing loss is seen and is due to fusion of the stapes to the petrous part of the temporal bone.