Duplication of the leg - Renal agenesis: Congenital malformation syndrome

A case is given of a male born with a duplication of the left leg and ipsil ateral kidney agenesis. Although the etiology is unknown, we believe this a ssociation represents a congenital malformation syndrome. It is a polytopic developmental field defect. The growth factor IGF-I produced by the interm ediary mesoderm or mesonephros (embryonary kidney) could be implicated in t he induction limb development and the application of FGF-8 protein to the f lank of young chick embryos inducing the development of additional limbs. I t is possible that one or more of the growth factors produced by the mesone phros take some cells of the intermediary mesoderm out of their renal way t o form a supernumerary limb.