An ectopic kidney is a birth defect in which a kidney is located in an abnormal position. In most cases, people with an ectopic kidney have no complaints. In other cases, the ectopic kidney may create urinary problems, such as urine blockage, infection, or urinary stones. Researchers estimate that ectopic kidney occurs once in every 1,000 births.
Sources
Kidney & Urology Foundation of America - Ectopic Kidney