From the Guidelines
Bartter syndrome, Gitelman's syndrome, and Liddle's syndrome are distinct genetic disorders affecting kidney function, with different characteristics and treatments, and accurate diagnosis is crucial for proper management. The main differences between these syndromes lie in their underlying causes, clinical presentations, and treatments.
- Bartter syndrome presents with hypokalemia, metabolic alkalosis, and normal to low blood pressure due to defects in sodium reabsorption in the thick ascending limb of the loop of Henle, often manifesting in childhood with growth retardation, muscle weakness, and polyuria 1.
- Gitelman's syndrome is milder, typically appearing in adolescence or adulthood, with similar electrolyte abnormalities plus hypomagnesemia and hypocalciuria due to defects in the distal convoluted tubule 1.
- Liddle's syndrome causes hypertension, hypokalemia, and metabolic alkalosis due to overactive epithelial sodium channels in the collecting duct, leading to excessive sodium reabsorption 1. Treatment for these syndromes varies:
- Bartter syndrome treatment includes potassium supplementation, NSAIDs like indomethacin, and potassium-sparing diuretics 1.
- Gitelman's syndrome management focuses on magnesium and potassium supplements, with potassium-sparing diuretics sometimes needed 1.
- Liddle's syndrome treatment involves amiloride or triamterene (potassium-sparing diuretics that block these channels) at standard doses, but not spironolactone since the renin-angiotensin-aldosterone system is suppressed 1. The key distinction is that Bartter and Gitelman's present with normal to low blood pressure and elevated renin and aldosterone levels, while Liddle's causes hypertension with suppressed renin and aldosterone levels, making accurate diagnosis crucial for proper management 1.
From the Research
Overview of Bartter Syndrome, Gitelman's Syndrome, and Liddle's Syndrome
- Bartter syndrome and Gitelman's syndrome are rare inherited autosomal recessive salt-losing tubulopathies characterized by severe and chronic hypokalemia associated with metabolic alkalosis and secondary hyperaldosteronism 2.
- Liddle's syndrome is not mentioned in the provided studies, however, Bartter syndrome and Gitelman's syndrome can be distinguished by their clinical manifestations and genetic mutations.
Clinical Manifestations
- Bartter syndrome results from a furosemide-like defect in sodium reabsorption in the Henle's loop leading to hypercalciuria and defect in urinary concentration capacity 2.
- Gitelman syndrome is a thiazide-like salt-losing tubulopathy associated with hypomagnesemia, hypocalciuria without defect in urinary concentration capacity 2.
- Clinical symptoms of Gitelman syndrome include tetany, delay in the height-weight growth curves, chronic tiredness, muscle weakness, myalgia and vertigo 2.
Diagnosis and Treatment
- The diagnosis of Bartter and Gitelman syndromes is based on clinical symptoms, biochemical markers, and genetic analysis 3.
- Treatment of Bartter and Gitelman syndromes consists of lifelong oral supplementations of potassium, salt (Bartter) and magnesium (Gitelman) 2.
- Indomethacin is efficient to reduce water and electrolyte loss in Bartter syndrome, while potassium-sparing diuretics may be helpful for severe hypokaliemia in Gitelman syndrome 2.
Genetic Mutations
- Bartter and Gitelman syndromes are caused by mutations in genes encoding electrolyte transport proteins located in the nephron, particularly in the Distal Convoluted Tubule and Ascending Loop of Henle 4.
- Different genetic mutations can result in distinct clinical manifestations, but there is considerable overlap between the phenotypes and genotypes of Bartter and Gitelman syndromes 3.
Prognosis and Management
- Patients with Bartter and Gitelman syndromes have a satisfactory prognosis during childhood, but decreased estimated glomerular filtration rate (eGFR) and pathologic proteinuria can occur in a large number of patients 5.
- Electrolyte abnormalities are most severe in patients with CLCNKB mutations, and fractional excretion of chloride prior to supplementation is a useful screening investigation in children with hypokalaemic alkalosis 5.