A 3-day-old male neonate is in the NICU with respiratory distress requiring mechanical ventilation. Prenatal ultrasound showed oligohydramnios and bilaterally enlarged, echogenic kidneys. Physical examination reveals bilateral flank masses and decreased urine output. Blood pressure is 95/65 mmHg (elevated for age). Postnatal renal ultrasound demonstrates bilaterally enlarged kidneys with smooth external contours, loss of corticomedullary differentiation, and numerous tiny cysts (<2 mm) arranged radially from the medulla to the cortex. Abdominal ultrasound shows periportal hyperechogenicity. Both parents underwent renal imaging, which was normal.
Which of the following is the most likely diagnosis?