Bartter, Gitelmann and Liddle syndrome

The order of the nephron defects in Bartter, Gitelmann and Liddle syndrome follows alphabetical order.

Bartter: Thick ascending LOH
Gitelmann: Distal tubule
Liddle: Collecting duct

a. Bartter syndrome: Thick ascending Loop of Henle (LOH)

• Defect in Na-2K-Cl transporter (like loop diuretics)
• NaCl wasting, Hypercalciuria and mild hypomagnesemia

Mnemonic: Loop diuretics lose calcium

b. Gitelmann syndrome: Distal tubule

• Defect in Na-Cl co-transporter (like thiazide diuretics)
• NaCl wasting, Hypocalciuria and Hypomagnesemia

Mnemonic: Thiazides preserve calcium

c. Liddle syndrome: Collecting duct

• Continuous activation of ENaC in collecting duct leading to increased Na absorption
• Early and severe hypertension with low renin and aldosterone
• Hypokalemia and metabolic alkalosis
• Amiloride or triamterene block ENaC (basis of treatment)

Important points to remember:

1. All of these cause hypokalemia and metabolic alkalosis.
2. Bartter and Gitelmann causes normotension or hypotension while Liddle causes hypertension.
3. Bartter’s syndrome causes hypercalciuria while Gitelmann’s syndrome causes hypocalciuria.
4. Gitelmann’s syndrome causes hpomagnesemia.
5. NSAIDs reduce polyuria and salt wasting in Bartter’s syndrome (increased renal PGE2 production in Bartter’s).
6. Bartter’s and Gitelmann’s are autosomal recessive (AR) while Liddle’s is autosomal dominant (AD).
7. In Bartter’s and Gitelmann’s there is secondary hyperaldosteronism and in Liddle’s, there is hypoaldosteronism.