The patient is a 33-year-old male, with a previous history of multiple renal calculi since childhood, with spontaneous and surgical passing. He was admitted for a new surgical procedure, when medical evaluation was requested, revealing hypocalcemia, hypophosphatemia and metabolic acidosis. He denied having used prescription or recreational drugs. A plain abdominal radiograph was performed, in supine position, anteroposterior projection (images 1 and 2).

 

Question:
Given the medical history and images presented, what is the most prominent abnormality in this patient’s renal parenchyma?

(Municipal Health Secretary – Piracicaba, São Paulo)

Metabolic acidosis is the excess of acidity in the blood, characterized by an abnormally low bicarbonate concentration. In the clinical evaluation of acid-base disorders, the differential diagnosis can be obtained by calculating the anion gap. 

Question: 
Which of the disorders below can cause a normal anion gap metabolic acidosis?