Renal System Practice Questions

A 4-year-old boy is brought to the pediatrician by his parents due to periorbital edema and scrotal swelling for the past 3 days. Physical examination reveals generalized pitting edema. Laboratory findings show: serum albumin 2.0 g/dL (normal 3.5-5.5), total protein 4.5 g/dL (normal 6.0-8.0), urine protein 4+ (random dipstick), and urine protein-to-creatinine ratio 5.2 (normal <0.2). Renal biopsy is performed. Which of the following is the most likely finding on electron microscopy?

A 30-year-old woman with a history of Sjögren's syndrome presents with muscle weakness and fatigue. Laboratory tests show serum potassium 2.8 mEq/L, bicarbonate 15 mEq/L, chloride 115 mEq/L, and anion gap 12 mEq/L. Arterial blood gas shows pH 7.28. Urine pH is 6.5. Which of the following renal tubular acidosis types is most consistent with these findings?

A 40-year-old man presents to the emergency department with acute onset severe right flank pain radiating to his groin. He reports nausea and has gross hematuria. Urinalysis shows numerous red blood cells and microscopic examination reveals birefringent, envelope-shaped crystals. Which of the following is the most likely composition of his kidney stone?