Tibial agenesis, femoral duplication, and caudal midline anomalies

Tibial agenesis with femoral duplication (Gollop-Wolfgang complex) and cloa cal exstrophy are each rare malformations. Thus, their concurrence in an in dividual is an extremely rare event. We report on a patient born with dista l duplication of the right femur, agenesis of the right tibia and hallux, c loacal exstrophy, and sacral defects. Review of the small group of cases re ported with femoral duplication and tibial agenesis in association with cau dal midline defects demonstrated a pattern of anomalies that while varying in presentation and severity was quite specific. We postulate that this dis order is related to misexpression of one or more distal HOX genes, potentia lly HOX10 or HOX11, leading to abnormal induction and proliferation of caud al mesenchyme, Am. J, Med. Genet. 85:13-19, 1999, (C) 1999 Wiley-Liss, Inc.