TY - JOUR
T1 - Nonacidotic kidney proximal tubulopathy with absorptive hypercalciuria
AU - Vezzoli, Giuseppe
AU - Corghi, Enzo
AU - Edefonti, Alberto
AU - Palazzi, Paola
AU - Dell'Antonio, Giacomo
AU - Elli, Attilio
AU - Azzani, Tiziana
AU - Vallino, Franca
AU - Bianchi, Giuseppe
PY - 1995
Y1 - 1995
N2 - We studied three patients with proximal tubulopathy characterized by defective reabsorption of phosphate, glucose, amino acids, urate, and low molecular weight proteins. This tubulopathy differs from Fanconi syndrome in that the patients had normal plasma bicarbonate and absorptive hypercalciuria associated with increased 1,25-dihydroxyvitamin D levels. The youngest patient was rachitic and may be classified with previously described patients, whereas the other two patients presented with nonrachitic osteopenic bone disease and their tubulopathy started during adult life. Kidney defects appeared sequentially in one of the nonrachitic patients. The two brothers of the youngest patient had similar kidney and bone disturbances. One of the other two patients had a brother with similar kidney reabsorption defects; an additional brother was probably affected and a sister presented with glycosuria, but no other reabsorption defects. The findings in these two families suggest a genetic transmission of proximal tubulopathy. The third case was sporadic. Renal histology of the three patients showed a great number of giant cells in the tubular lumen. We conclude that, at least in our adult patients, tubulopathy may represent a new entity among the proximal tubular dysfunction cases described to date. The features of this proximal defect suggest that it may be caused by a selective alteration of luminal cell membrane transport of phosphate, glucose, amino acids, urate, and proteins in the presence of a normal sodium gradient across the tubular cell membrane.
AB - We studied three patients with proximal tubulopathy characterized by defective reabsorption of phosphate, glucose, amino acids, urate, and low molecular weight proteins. This tubulopathy differs from Fanconi syndrome in that the patients had normal plasma bicarbonate and absorptive hypercalciuria associated with increased 1,25-dihydroxyvitamin D levels. The youngest patient was rachitic and may be classified with previously described patients, whereas the other two patients presented with nonrachitic osteopenic bone disease and their tubulopathy started during adult life. Kidney defects appeared sequentially in one of the nonrachitic patients. The two brothers of the youngest patient had similar kidney and bone disturbances. One of the other two patients had a brother with similar kidney reabsorption defects; an additional brother was probably affected and a sister presented with glycosuria, but no other reabsorption defects. The findings in these two families suggest a genetic transmission of proximal tubulopathy. The third case was sporadic. Renal histology of the three patients showed a great number of giant cells in the tubular lumen. We conclude that, at least in our adult patients, tubulopathy may represent a new entity among the proximal tubular dysfunction cases described to date. The features of this proximal defect suggest that it may be caused by a selective alteration of luminal cell membrane transport of phosphate, glucose, amino acids, urate, and proteins in the presence of a normal sodium gradient across the tubular cell membrane.
KW - Hypercalciuria
KW - hypophosphatemia
KW - kidney proximal tubule
KW - nephrolithiasis
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U2 - 10.1016/0272-6386(95)90002-0
DO - 10.1016/0272-6386(95)90002-0
M3 - Article
C2 - 7847348
AN - SCOPUS:0028891811
VL - 25
SP - 222
EP - 227
JO - American Journal of Kidney Diseases
JF - American Journal of Kidney Diseases
SN - 0272-6386
IS - 2
ER -