A new distal arthrogryposis syndrome characterized by plantar flexion contractures

The distal arthrogryposis (DA) syndromes are a distinct group of disorders characterized by contractures of two or more different body areas. More than a decade ago, we revised the classification of DAs and distinguished several new syndromes. This revision has facilitated the identification of five genes (i.e., TNNI2, TNNT3, MYH3, MYH8, and TPM2) that encode components of the contractile apparatus of fast-twitch myofibers and cause DA syndromes. We now report on the phenotypic features of a novel DA disorder characterized primarily by plantar flexion contractures in a large five-generation Utah family. Contractures of hips, elbows, wrists, and fingers were much milder though they varied in severity among affected individuals. All affected individuals had normal neurological examinations; electromyography and creatinine kinase levels were normal on selected individuals. We have tentatively labeled this condition distal arthrogryposis type 10 (DA10).