Renal Tubulopathies (inherited)

Exam Cram

• Bartter, Gitelman & Liddle's syndromes (BGL)- hypokalaemic metabolic alkalosis

• Bartter: normotensive, normal magnesium

• Gitelman: normotensive, low magnesium, 

• Liddle's: hypertensive (& young), normal magnesium

Learnt these for specialty exams, not finals!

Outline

I remember the mnemonic BGL, because that is the order of their pathophysiology from proximal to distal!

Bartter's Syndrome

Electrolytes: Hypokalaemia, normal Mg/ Calcium

BP: Normotensive

Location: Thick ascending loop of Henle

Transporter: Na-K-2Cl

Raised urinary calcium

Gitelman's Syndrome 

Presentation: Young + tiredness, limb weakness

Electrolytes: Hypokalaemia, hypo Mg/ Calcium

BP: Normotensive

Gene defect: SLC12A3 

Moa: DCT (thiazide) NaCl transporter leaking electrolytes

Management: PO K+ supplements

Differentiating Gitelman's vs Bartter's: 

Age of presentation

• If above 18yrs: Gitelman's

• Below 18yrs: Bartter's

Liddle's Syndrome

Electrolytes: Hypokalaemia, normal Mg/ Calcium

BP: Hypertensive

Gene: SCNN1B

Location Collecting duct Na+ defect

Management: 1. Amiloride, 2. ACE inhibitors

*

Management

• Replacement of potassium (and calcium / magnesium as required)

• Renal consult (!)

• As per cause

References

1. Mubarik A, Anastasopoulou C, Aeddula NR. Liddle Syndrome (Pseudohyperaldosteronism) [Updated 2024 Mar 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK536911/