A 35-year-old woman presents with recurrent renal calculi (calcium oxalate stones), hypophosphataemia, phosphaturia, and proximal renal tubular dysfunction (glycosuria with normoglycaemia, aminoaciduria, uricosuria). The MOST likely unifying diagnosis is:
- A Primary hyperparathyroidism
- B Fanconi syndrome (proximal renal tubular acidosis with generalised proximal tubular dysfunction) ✓
- C Distal renal tubular acidosis (Type 1 RTA)
- D Bartter syndrome
Correct answer: B. Fanconi syndrome (proximal renal tubular acidosis with generalised proximal tubular dysfunction)
Explanation
Fanconi syndrome represents generalised proximal tubular dysfunction with impaired reabsorption of glucose, amino acids, uric acid, phosphate, bicarbonate, and small-molecular-weight proteins — producing the triad of glycosuria/normoglycaemia, aminoaciduria, and phosphaturia. Hypophosphataemia leads to rickets/osteomalacia. Causes include cystinosis (most common in children), Wilson's disease, multiple myeloma, and antiretroviral drugs (tenofovir). Type 1 RTA affects only H⁺ secretion in the distal tubule. Bartter syndrome presents with hypokalaemic alkalosis.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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