 Hyperphosphaturia in the Jentsch model was associated with decreased apical expression of the sodium/phosphate cotransporter NaPi2a that is the predominant phosphate transporter in the proximal tubule.However, NaPi2a expression is ClC-5-independent since apical NaPi2a was normally expressed in any proximal tubules of chimeric female mice, while it was decreased in all male proximal tubular knock-out cells.Serum parathormone (PTH) is normal in knock-out mice while urinary PTH is increased of about 1.7 fold.