Clinical analysis of a variant of Freeman-Sheldon syndrome (DA2B).

We describe the clinical characteristics of a provisionally unique form of distal arthrogryposis. The anomalies observed in affected individuals are more severe than those in distal arthrogryposis type 1 and are similar to but less dramatic than those described in distal arthrogryposis type 2A (Freeman-Sheldon syndrome). Consequently, we label this disorder distal arthrogryposis type 2B (DA2B). Affected individuals have vertical talus, ulnar deviation, severe camptodactyly, and a distinctive face characterized by a triangular shape, prominent nasolabial folds, downslanting palpebral fissures, small mouth, and a prominent chin. A gene for DA2B maps to chromosome 11p15.5. We suggest that DA2B is partly responsible for the clinical variability observed in Freeman-Sheldon syndrome.