Prevalence of Liddle Syndrome Among Young Hypertension Patients of Undetermined Cause in a Chinese Population.

Abstract

Liddle syndrome, an autosomal dominant form of monogenic hypertension, has been regarded as a rare disorder, which leads to many Liddle syndrome patients being misdiagnosed and experiencing severe complications at an early age. Little is known about the prevalence of Liddle syndrome. In this study, the authors investigated the prevalence of Liddle syndrome confirmed by genetic testing among young hypertension patients of undetermined causes in China. A total of 330 hypertensive patients aged 14 to 40 years after exclusion of common secondary causes of hypertension were enrolled and serum potassium concentrations were measured. Patients with hypokalemia underwent genetic testing of the 13th exon of genes encoding β and γ subunits of the epithelial sodium channel (ENaC). Diagnosis was established by identification of mutations that destroy the PY motif of ENaC. Five patients were diagnosed with Liddle syndrome (prevalence, 1.52%), as well as 12 of their relatives. These patients with Liddle syndrome presented with an earlier onset of hypertension, a stronger family history of hypertension, and higher blood pressure than those with essential hypertension. All patients had hypokalemia and suppressed plasma renin activity. The results demonstrated that Liddle syndrome is an important etiology of hypertension in this young population. Screening of Liddle syndrome should focus on young hypertension patients, particularly those with early penetrance, hypokalemia, and low renin levels after exclusion of common secondary causes.