From the Guidelines
Bartter syndrome is diagnosed through a combination of clinical features, laboratory findings, and genetic testing, with treatment focusing on correcting electrolyte abnormalities and blocking the renin-angiotensin-aldosterone system, as recommended by the European Rare Kidney Disease Reference Network Working Group for Tubular Disorders 1.
Diagnostic Criteria
The diagnostic criteria for Bartter syndrome include:
- Hypokalemia
- Metabolic alkalosis
- Normal blood pressure despite elevated renin and aldosterone levels
- Increased urinary excretion of potassium, chloride, and prostaglandins
- Additional findings may include hypercalciuria, nephrocalcinosis, and growth retardation in children
Treatment Options
Treatment for Bartter syndrome focuses on correcting electrolyte abnormalities and blocking the renin-angiotensin-aldosterone system, and may include:
- Potassium supplementation (typically 2-4 mEq/kg/day)
- Potassium-sparing diuretics like spironolactone (1-3 mg/kg/day) or amiloride (0.3-0.6 mg/kg/day)
- NSAIDs, particularly indomethacin (1-3 mg/kg/day), to reduce prostaglandin production and improve electrolyte balance
- Magnesium supplementation, as magnesium deficiency commonly accompanies the condition
- ACE inhibitors like enalapril (0.1-0.5 mg/kg/day) to control aldosterone effects
Genetic Testing
Genetic testing is recommended to confirm the diagnosis of Bartter syndrome, and should include genes such as SLC12A1, KCNJ1, CLCNKB, BSND, and MAGED2 1.
Monitoring and Follow-up
Regular monitoring of electrolytes, kidney function, and growth parameters is essential, with dose adjustments based on clinical response, as recommended by the European Rare Kidney Disease Reference Network Working Group for Tubular Disorders 1.
From the Research
Diagnostic Criteria for Bartter Syndrome
- The clinical presentation of Bartter syndrome (BS) is heterogeneous, with a wide variety of genetic variants 2
- Main clinical and biochemical alterations in BS include polyuria, dehydration, hypokalemia, hypochloremic metabolic alkalosis, hyperreninemia, high levels of prostaglandins, normal or low blood pressure, hypercalciuria, and failure to thrive 3
- The onset age of Bartter syndrome can range from 13-35 years old, with main symptoms including weakness, paralysis, numbness, and tetany 4
- Laboratory findings may include persistent hypokalemia, metabolic alkalosis, and hyperreninemia 4
Treatment Options for Bartter Syndrome
- Treatment focuses mainly on correcting dehydration and electrolyte disturbances, and measures to reduce polyuria, including the use of nonsteroidal anti-inflammatory medications to control excessive renal prostaglandin E2 production 3
- Commonly used treatments include indomethacin, potassium chloride supplements, and spironolactone 2
- Potassium and magnesium supplementation, or in combination with prostaglandin synthetase inhibitor, aldosterone antagonist, and immunosuppressant, may also be effective 4
- Amiloride, a potassium-sparing diuretic, may be a useful and safe drug for the treatment of hypokalemia in BS 5
Genetic Variants and Classification
- BS can be classified into different types based on the genetic variants, including Type I, II, III, IV, and V 2, 3
- Type III BS is caused by mutations in the CLCNKB gene, and may present with a synonymous mutation 6
- Molecular studies have identified different subtypes of BS, and the classification of BS can be based on the time of onset and symptoms, including antenatal and classic BS 3