Hereditary Symphalangism Associated with Carpal and Tarsal Fusions

Abstract

This presentation discusses symphalangism and describes the disease in 5 members from four generations of a family of 17. In all 5, there were carpal and tarsal fusions. Symphalangism is an hereditary anomaly manifested by partial or total absence of one or more interphalangeal joints, with fusion of the involved phalanges. The term was first used by Cushing (1), although the entity was described earlier and has been known by many names: congenital ankylosis, aplasia of the interphalangeal joints, phalangeal anarthrosis, and hereditary multiple ankylosing arthropathy. The cause of symphalangism is failure of differentiation of the interphalangeal joint, which normally occurs about the eighth week of fetal life (6). The defect has been traced through several generations and occurs in half the members of an involved family (2, 3). It is not sex-linked but follows a simple dominant mendelian type of transmission. Sites of predilection are the proximal interphalangeal joints in the fingers and the distal inte...