Liddle syndrome presenting with normal aldosterone levels: A case report.

INTRODUCTION: Liddle syndrome is an autosomal dominant disorder characterized by hypertension, hypokalemia, low aldosterone levels, and reduced renin activity. Atypical Liddle syndrome can be easily misdiagnosed due to its clinical phenotypes resembling hyperaldosteronism.

PATIENT CONCERN: The patient was diagnosed with primary aldosteronism due to hypertension and hypokalemia, and underwent left adrenalectomy. After the operation, the patient still had hypertension and hypokalemia that were not easy to control and correct, and had acute cerebral infarction.

DIAGNOSIS: The genetic test showed that the base duplication in the coding region of SCN1B gene caused a frameshift mutation:c.1789dupC (p.Arg597fs), Liddle syndrome was diagnosed.

INTERVENTION AND OUTCOMES: The patient was treated with a low-sodium diet and oral triamterene. The serum potassium level returned to normal and the blood pressure was controlled.

LESSONS: Some Liddle syndrome may present with normal aldosterone levels, genetic testing is necessary for the diagnosis. If the diagnostic test of primary aldosteronism is positive, but the treatment with spironolactone is ineffective, we should actively search for other causes.