Fanconi syndrome features include which of the following?

Fanconi syndrome features include which of the following?

• A. Phosphaturia, glucosuria, uricosuria, aminoaciduria
• B. Phosphaturia, glycosuria, uricosuria, proteinuria
• C. Hyperphosphatemia, glycosuria, hypouricosuria, aminoaciduria
• D. Phosphaturia, glycosuria, uricosuria, proteinuria

Answer: (A)

Fanconi syndrome reflects proximal tubular reabsorption failure, so substances normally reclaimed in the proximal tubule are lost in the urine. In this setting you see phosphaturia (loss of filtered phosphate leading to low serum phosphate), glycosuria with normal blood glucose, aminoaciduria (loss of filtered amino acids), and uricosuria (loss of uric acid). These are the classic hallmarks of proximal tubule dysfunction. Proteinuria can occur with tubular disorders, but it's not a defining feature of Fanconi syndrome in the way the four solutes are. The other patterns—hyperphosphatemia or hypouricosuria, for example—don’t fit the mechanism: the tubule’s failure to reabsorb phosphate and other solutes explains the observed urinary losses and the associated metabolic consequences.

Fanconi syndrome reflects proximal tubular reabsorption failure, so substances normally reclaimed in the proximal tubule are lost in the urine. In this setting you see phosphaturia (loss of filtered phosphate leading to low serum phosphate), glycosuria with normal blood glucose, aminoaciduria (loss of filtered amino acids), and uricosuria (loss of uric acid). These are the classic hallmarks of proximal tubule dysfunction.

Proteinuria can occur with tubular disorders, but it's not a defining feature of Fanconi syndrome in the way the four solutes are. The other patterns—hyperphosphatemia or hypouricosuria, for example—don’t fit the mechanism: the tubule’s failure to reabsorb phosphate and other solutes explains the observed urinary losses and the associated metabolic consequences.