Last reviewed 06/2022

The defect RTA-I prevents the distal tubule from generating, or maintaining, the normal 900:1 hydrogen ion concentration gradient across its wall.

Systemic acidosis results in calcium resorption from bone and hypercalciuria.

Nephrocalcinosis and urinary stones are common, being the result of:

  • hypercalciuria
  • alkaline urine: calcium phosphate tends to precipitate out in alkaline urine
  • low urinary citrate excretion: citrate chelates calcium and reduces precipitation

Hypokalaemia results from:

  • a lack of intraluminal hydrogen ions, resulting in exchange of potassium for luminal sodium
  • increased sodium losses, resulting in secondary hyperaldosteronism and hence hypokalaemia