Femur, Unilateral Bifid, with Monodactylous Ectrodactyly, also known as gollop-wolfgang complex, is related to tibial hemimelia and split hand-foot malformation. An important gene associated with Femur, Unilateral Bifid, with Monodactylous Ectrodactyly is BHLHA9 (Basic Helix-Loop-Helix Family Member A9). Affiliated tissues include bone and heart, and related phenotypes are bifid femur and ectrodactyly