ABSTRACT
A1 E All the abnormalities listed are associated with renal ectopia except those of the pronephros. The fetal kidney develops from the metanephros. The ureteric bud develops from the mesonephros, and its cranial section merges with the developing metanephros anteriorly. In the ensuing month, this fused mass migrates cephalically, undergoing a final medial rotation of 90 degrees. During ascent, the cephalic end of the ureteric bud divides to form the pelvicalyceal system. During ascent, the blood supply of the kidney is drawn from local vessels. Any deviation from this process will lead to anomalies of renal position and fusion.
