Fanconi syndrome involves a global proximal tubular dysfunction. Which combination of urinary losses is pathognomonic?

• A Hyperchloraemic acidosis with K+ retention and distal tubular dysfunction
• B Nephrotic-range proteinuria with Na and Cl wasting
• C Uricosuria and nephrocalcinosis from distal tubular Ca2+ wasting
• D Phosphaturia, glucosuria, aminoaciduria, uricosuria, and proximal renal tubular acidosis ✓

Explanation

Fanconi syndrome reflects global proximal tubular dysfunction with impaired reabsorption of all proximal tubule-dependent substances: glucose (glucosuria despite normal blood glucose), amino acids (aminoaciduria), uric acid (uricosuria), phosphate (phosphaturia causing hypophosphataemia and rickets), and bicarbonate (proximal or type 2 RTA). Causes include Wilson's disease, Lowe syndrome, multiple myeloma, and antiretroviral drugs (tenofovir). The combination of phosphaturia + glucosuria + aminoaciduria + proximal RTA is diagnostic.

Reference: Guyton & Hall, Textbook of Medical Physiology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.