From the Guidelines
Liddle Syndrome
Liddle syndrome is a rare genetic disorder characterized by excessive sodium absorption and water retention, leading to hypertension and hypokalemia 1.
Key Features
The key features of Liddle syndrome include:
- Suppressed plasma renin activity (PRA)
- Increased sodium absorption in the distal tubule
- Serum potassium abnormalities
- Metabolic acid-base disturbances
- Abnormal plasma aldosterone concentrations 1
Treatment
The primary treatment for Liddle syndrome involves the use of potassium-sparing diuretics, such as triamterene (50-100 mg daily) or amiloride (5-10 mg daily), to help reduce sodium absorption and increase potassium levels 1. Additionally, patients may be advised to follow a low-sodium diet and restrict their sodium intake to less than 2 grams per day.
Management
In some cases, other medications such as spironolactone (25-50 mg daily) may be used off-label to help manage the condition 1. It is essential to monitor blood pressure, electrolyte levels, and kidney function regularly while on treatment. Lifestyle modifications, including regular exercise, weight management, and stress reduction, can also help manage the condition 1. Patients with Liddle syndrome should work closely with their healthcare provider to develop a personalized treatment plan and make adjustments as needed to achieve optimal blood pressure control and prevent long-term complications.
From the Research
Definition and Characteristics of Liddle Syndrome
- Liddle syndrome, also known as pseudohyperaldosteronism, is a rare autosomal dominant disease that mimics primary hyperaldosteronism 2, 3, 4, 5, 6.
- It is characterized by early-onset hypertension, hypokalemia, and hypoaldosteronism, caused by excessive salt and water reabsorption in the distal nephron 2, 3.
- The syndrome is often associated with hyporeninemia and suppressed aldosterone secretion, which can lead to metabolic alkalosis 3, 4, 5, 6.
Causes and Molecular Mechanisms
- Liddle syndrome is caused by mutations in the genes encoding the subunits of the Epithelial Sodium Channel (ENaC), specifically SCNN1A, SCNN1B, and SCNN1G 3, 4, 6.
- These mutations can lead to an increase in ENaC activity, resulting in excessive sodium reabsorption and subsequent hypertension and hypokalemia 3, 4, 6.
Diagnosis and Treatment
- Liddle syndrome can be diagnosed clinically by phenotype and confirmed through genetic testing 3, 5, 6.
- Treatment typically involves the use of potassium-sparing diuretics, such as amiloride and triamterene, which can reduce ENaC activity and restore normotension and electrolyte balance 3, 4, 6.
- A reduced sodium diet is also often recommended as part of the treatment plan 3.