Hereditary symphalangism with associated tarsal synostosis and hypophalangism.

Symphalangism is a rare genetic condition that may represent the earliest documentation of mendelian inheritance in man. The disorder results in interphalangeal joint fusion in the hands and feet. The authors review this rare condition and present a case study consisting of four generations with 15 affected family members. The association of multiple tarsal synostosis and the previously unreported associated occurrence of pedal hypophalangism in this pedigree is presented.