Renal tubular defects FA 533

Question 1

Fanconi syndrome

where is the defect?
what are the results?
causes?

Answer 1

reaborptive defect in PCT
- results in metabolic acidosis – proximal renal tubular aciosis

• causes include hereditary defects (wilson disease, tyrosinemia, glycogen storage disease) , ischemia, multiple myeloma, nephrotoxins/drugs, lead poisoning

Question 2

Bartter syndrome

where is the defect?
causes?
what are the results?

Answer 2

• Reabsorptive defect in thick ascending loop of Helenle.
• Autosomal recessive affects NKCC transporter

hypokalemia, metabolic alkalosis with hypercalciuria

Question 3

Gitelman syndrome

where is the defect?
causes?
what are the results?

Answer 3

Reabsorptive defect in NaCl in DCT

• Autosomal recessive (less severe than Bartter)
• hypokalemia, hypomagnesium, metabolic alkalosis, hypocalciuria

Question 4

Liddle syndrome

where is the defect?
causes?
what are the results?
tx?

Answer 4

Gain of function mutation in Na+ channel in the collecting tubules

• Autosomal dominant
• hypertension, hypokalemia, metabolic alkalosis, decrease aldosterone

treatment: Amiloride

Question 5

Syndrome of apparent mineralocorticoid excess

Causes?
What happens?
why does it happen?
Can you get this another way aka acquired?

Answer 5

Hereditary deficiency of 11 beta- hydroxysteroid dehydrogenase in mineralocorticoid receptor containing cells.

• 11 beta- hydroxysteroid dehydrogenase usually converts cortisol to cortisone.

Excess cortisol in cells = hypertension, hypokalemia, metabolic alkalosis, low aldosterone levels

acquired from glycyrrhetic acid (licorice)