RESUMO
Liddle's syndrome is a rare inherited disease with characteristic clinical manifestations of hypertension and hypokalemic metabolic alkalosis. Markedly suppressed serum aldosterone and renin levels are important laboratory findings to differentiate this disorder from primary hyperaldosteronism. When Liddle et al. reported the disorder in 1963, they proposed aggressive Na+ absorption and increased excretion of K+ as the pathogenesis of the syndrome. Since then, specific mutation in the epithelial Na+ channel located in the collecting duct of the kidney has been elucidated as a disease mechanism. Liddle's syndrome is inherited by an autosomal dominant trait and generally the onset of the syndrome is before the age of 20 with increased risk of premature death due to stroke or heart failure. Recently, however, a few cases of late onset and genetically proven nonfamilial cases with de novo mutation of beta or gamma Na+ channel have been reported. We report a case of seventy-one year old woman who had hypertension with hypokalemic metabolic alkalosis and was diagnosed as Liddle's syndrome. Further evaluation revealed low serum renin and aldosterone levels. Primary aldosteronism, Cushing's syndrome, glucocorticoid remediable aldosteronism and deficiency of 11beta-OHase and 17alpha-OHase were ruled out based on her laboratory data and history. Her hypertension and hypokalemia responded to amiloride treatment but not to spironolactone.