Renal

Question 1

Explain Type 1 RTA

Answer 1

Inability to generate acid urine (secrete H+) in distal tubule
causes hypokalaemia

Complications include nephrocalcinosis and renal stones

Causes include idiopathic, rheumatoid arthritis, SLE, Sjogren’s, amphotericin B toxicity, analgesic nephropathy

Question 2

Explain Type 2 RTA

Answer 2

Decreased HCO3- reabsorption in proximal tubule
causes hypokalaemia

Complications include osteomalacia

Causes include idiopathic, as part of Fanconi syndrome, Wilson’s disease, cystinosis, outdated tetracyclines, carbonic anhydrase inhibitors (acetazolamide, topiramate)

Question 3

Explain Type 3 RTA

Answer 3

extremely rare - results in hypokalaemia

Caused by carbonic anhydrase II deficiency

Question 4

Type 4 RTA

Answer 4

A reduction in aldosterone leads, in turn, in a decrease in proximal tubular ammonium excretion

Causes hyperkalaemia

Causes include hypoaldosteronism, diabetes