Familial inheritance of crossed fused renal ectopia.

A family with dominant inheritance of a rare renal malformation is reported. The father and one son had left crossed fused ectopic and dysplastic kidneys and another son had a horseshoe kidney and vesicoureteral reflux. We discuss various potential pathogenetic mechanisms and propose that a defect in the timing of the proper reciprocal induction of the ureteric bud and the metanephric blastema is involved.