What is Bartter Syndrome?
Bartter Syndrome is a rare inherited kidney disorder affecting the body’s ability to reabsorb electrolytes, leading to significant imbalances. Understanding its etiopathogenesis, clinical manifestations, and management is crucial for early diagnosis and better outcomes.
Etiopathogenesis of Bartter Syndrome
Bartter Syndrome arises due to mutations in genes that regulate ion channels in the renal tubules. These genetic defects disrupt sodium, potassium, and chloride reabsorption in the loop of Henle.
Types of Bartter Syndrome:
- Type I and II: Mutations in SLC12A1 and KCNJ1 genes.
- Type III: Mutations in CLCNKB gene.
- Type IV: Associated with BSND gene, also causing sensorineural deafness.
- Type V: Mutations in CASR gene, leading to calcium-sensing abnormalities.
Key features include:
- Loss of sodium and potassium.
- Secondary hyperaldosteronism.
- Activation of the renin-angiotensin-aldosterone system (RAAS).
Clinical Manifestations of Bartter Syndrome
Symptoms usually present in infancy or childhood but vary by subtype.
- Prenatal Signs: Polyhydramnios, prematurity.
- Early Childhood Symptoms:
- Growth retardation.
- Failure to thrive.
- Electrolyte Imbalance Symptoms:
- Hypokalemia: Muscle weakness, fatigue.
- Hypochloremia: Metabolic alkalosis.
- Hypercalciuria: Risk of nephrocalcinosis and kidney stones.
Additional signs include excessive thirst (polydipsia) and frequent urination (polyuria).
Management of Bartter Syndrome
Treatment aims to correct electrolyte imbalances and improve quality of life.
- Dietary Management:
- High potassium and sodium intake.
- Adequate hydration to manage polyuria.
- Pharmacological Treatment:
- Potassium-sparing diuretics: Spironolactone or amiloride.
- Non-steroidal anti-inflammatory drugs (NSAIDs): Indomethacin to reduce prostaglandin synthesis.
- Magnesium Supplements: For associated hypomagnesemia.
- Growth Hormone Therapy:
- For severe growth retardation.
- Regular Monitoring:
- Electrolyte levels.
- Renal function.
- Genetic Counseling:
- Recommended for families with a history of the syndrome.
