Laboratory for Molecular Diagnostics
Center for Nephrology and Metabolic Disorders

Proximal symphalangism 1B

Symphalangism of the Cushing type 1B is an autosomal dominant disorder caused by mutations of the GDF5 gene. It is characterized by fusion of proximal interphalangeal joints, carpals, tarsals, and sometimes conductive hearing loss.


Proximal symphalangism
Proximal symphalangism 1A
Proximal symphalangism 1B



Seemann P et. al. (2005) Activating and deactivating mutations in the receptor interaction site of GDF5 cause symphalangism or brachydactyly type A2.


Wang X et. al. (2006) A novel mutation in GDF5 causes autosomal dominant symphalangism in two Chinese families.


Yang W et. al. (2008) Novel point mutations in GDF5 associated with two distinct limb malformations in Chinese: brachydactyly type C and proximal symphalangism.

Update: Sept. 26, 2018