Updated: 12/1/2021

Liddle Syndrome

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  • Snapshot
    • A 12-year-old girl is brought to the emergency department due to nausea and vomiting over the course of a few days. Her blood pressure is 140/103 mmHg. Laboratory testing is significant for hypokalemia, metabolic alkalosis, and undetectable levels of renin and aldosterone.
  • Introduction
    • Clinical definition
      • a renal tubular disorder affecting the collecting tubules characterized by
        • hypertension
        • hypokalemia
        • metabolic alkalosis
      • also known as pseudohyperaldosteronism
  • Epidemiology
    • Incidence
      • rare
    • Demographics
      • young children
        • suspected if there is early onset hypertension
      • may not be detected until adulthood
    • Risk factors
      • family history of early onset hypertension or hypokalemia may suggest Liddle’s
  • Etiology
    • Pathogenesis
      • gain of function mutation involving the epithelial Na+ channel (ENaC) resulting in
        • increased Na+ reabsorption in the collecting tubules
          • this causes the lumen to be electronegative and causes a gradient that favors secretion of K+ into the lumen
            • this results in decreased K+
        • mimics hyperaldosteronism (recall that aldosterone increases the number of open luminal Na+ channels)
    • Genetics
      • inheritance pattern
        • autosomal dominant
      • mutations
        • chromosome 16p12
  • Presentation
    • Symptoms
      • triad presenting at a young age
        • hypertension
        • hypokalemia
        • metabolic alkalosis
    • Physical exam
      • hypertension
  • Studies
    • Labs
      • hypokalemia
      • metabolic alkalosis
      • ↓ aldosterone
      • ↓ renin
      • genetic testing
        • most definitive diagnosis
  • Differential
    • Primary hyperaldosteronism
    • Congenital adrenal hyperplasia
    • Renal Tubular Defects
      Category
      Fanconi Syndrome
      Bartter SyndromeGitelman SyndromeLiddle Syndrome
      Defect localization
      • Proximal tubule
      • Thick ascending loop of Henle
      • Distal convoluted tubule
      • Collecting tubule
      Etiology
      • Wilson disease
      • Tyrosinemia
      • Cystinosis
      • Multiple myeloma
      • Galactosemia
      • Mitochondrial myopathies
      • Medications
        • aminoglycosides
        • cisplatin
        • ifosfamide
        • valproic acid
      • Heavy metals
        • mercury
        • lead
      • Autosomal recessive mutation involving the NKCC2 cotransporter
      • Autosomal recessive mutationinvolving the NaCl cotransporter
      • Autosomal dominant mutation leading to increased activity of ENaC
      Findings
      • Hypophosphatemia
      • Aminoaciduria
      • Renal glucosuria
      • Tubular proteinuria
      • Proximal renal tubular acidosis
      • Hypokalemia
      • Hypochloremia
      • Metabolic alkalosis
      • Normotension
      • Elevated plasma renin level
      • Hypokalemia
      • Hypochloremia
      • Metabolic alkalosis
      • Hypomagnesemia
      • Hypocalciuria
      • Normotension
      • Hypertension
      • Hypokalemia
      • Metabolic alkalosis
  • Treatment
    • Medical
      • potassium-sparing diuretics
        • indication
          • for all with Liddle syndrome
          • recall that both drugs directly blocks Na+ channels in the collecting tubules
        • drugs
          • amiloride
          • triamterene
  • Complications
    • Cardiac arrhythmia due to hypokalemia
  • Prognosis
    • Very good with treatment
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