Distal arthrogryposis type 1: clinical analysis of a large kindred.

We describe the clinical findings of 15 individuals in a large kindred affected with distal arthrogryposis type 1A (DA1A). The most consistent findings among individuals were overlapping fingers at birth, abnormal digital flexion creases, and foot deformities, including talipes equinovarus and vertical talus. There was marked intrafamilial variation in the expression of DA1A. Linkage mapping of the locus for DA1A suggests that the use of strict diagnostic criteria excludes unaffected individuals rigorously, but can produce incomplete ascertainment of affected individuals. In the context of an affected family, the range of phenotypes consistent with a diagnosis of DA1A needs to be expanded.