A 2-day-old male infant is hospitalized in the intensive care unit with acute respiratory distress. Radiographic examination reveals that the patient has anuria, oligohydramnios, and hypoplastic lungs. Facial characteristics are consistent with Potter syndrome. Which of the following is the most likely explanation for these initial findings?

Potter sequence, or Potter syndrome, is a rare autosomal recessive trait and is associated with renal agenesis or hypoplasia. Altered facial characteristics include flattened nasal bridge, mandibular micrognathia, malformed low-set ears, etc. Absence or lack of proper development of the kidneys causes oligohydramnios, or possibly anhydramnios. Multicystic dysplastic kidney and polycystic kidney are usually secondary to Potter sequence and are therefore not the cause of Potter sequence or oligohydramnios. Wilms tumor is a relatively common renal tumor that presents in children; it is not associated with oligohydramnios and Potter sequence. Extrophy of the bladder is a congenital defect that exposes the posterior surface of the bladder on the exterior of the abdominal wall; there is no indication of this defect in the patient.