Q. A 6-month-old male is brought to the pediatrician by his parents for a routine check-up. He was born at full-term and has been growing normally, but his parents noticed that his belly has been getting bigger in the past few weeks. On examination, the pediatrician observes that the baby has a distended abdomen and that his kidneys are enlarged and palpable. Laboratory tests reveal that the baby has anemia and high levels of creatinine in his blood. An ultrasound confirms the presence of numerous cysts in both kidneys. What is the most likely diagnosis for this 6-month-old baby boy?