IHH and multiple synostoses syndrome: Here we describe a novel GDF5 Trp to Arg transition (p.W414R) in patients with multiple synostoses syndrome 2 (SYNS2), including proximal and distal symphalangism, metacarpophalangeal synostosis, and synostosis of carpal and tarsal bones as well as BDA1 with severe hypoplasia and even aplasia of the middle phalanges.