<prompt> Which of the following is the most common renal cystic disease in infants is -Polycystic kidneySimple renal cystUnilateral renal dysplasiaCalyceal cyst  <response>: In unilateral renal dysplasia, one kidney does not develop properly in the womb. Unilateral means one side. Most children born with one dysplastic kidney have no complications and do not need special treatment. Sometimes the other kidney grows larger than normal to make up for the dysplastic kidney Ref Harrison20th edition pg 267 