Symphalangism, Proximal, 1a (SYM1A)

Symphalangism, Proximal, 1a, also known as hereditary absence of the proximal interphalangeal joints, is related to symphalangism, proximal, 1b and tarsal-carpal coalition syndrome. An important gene associated with Symphalangism, Proximal, 1a is NOG (Noggin). Affiliated tissues include bone and eye, and related phenotypes are conductive hearing impairment and tarsal synostosis