Dent disease: A window into calcium and phosphate transport

Area of Science:

• Nephrology
• Molecular Biology
• Genetics

Background:

• Dent disease type 1 (DD1) stems from mutations in the CLCN5 gene, affecting the ClC-5 chloride/proton antiporter in proximal tubule endosomes.
• DD1 is characterized by low molecular weight proteinuria, hypercalciuria, and chronic kidney disease, with less common occurrences of kidney stones and rickets.

Purpose of the Study:

• To review calcium and phosphate transport in the kidney focusing on Dent disease.
• To explore how ClC-5 dysfunction impacts calcium and phosphate metabolism and identify potential mechanisms for hypercalciuria and kidney stones.

Main Methods:

• Review of existing literature on Dent disease, CLCN5 gene, ClC-5 function, and kidney transport.
• Examination of evidence from ClC-5 knockout models regarding parathormone endocytosis and sodium/proton exchanger NHE3 expression.

Main Results:

• ClC-5 dysfunction in DD1 may disrupt proximal tubule endocytosis, crucial for calcium and phosphate reabsorption.
• Evidence suggests ClC-5 mediates parathormone endocytosis and influences NHE3 expression, affecting sodium and calcium transport.
• NHE3 dysfunction, potentially linked to DD1, has not been previously investigated but could explain renal sodium wasting.

Conclusions:

• Insights from Dent disease highlight the critical role of ClC-5 in kidney calcium and phosphate homeostasis.
• ClC-5 dysfunction and potential associated NHE3 alterations offer a novel perspective on hypercalciuria and idiopathic calcium nephrolithiasis.
• Further investigation into NHE3's role in DD1 is warranted to fully understand the disease phenotype.