Two Male Siblings with Pseudohypoaldosteronism Type I

ABSTRACT

Pseudohypoaldosteronism (PHA) is rare herediary salt wasting syndrome due to peripheral resistance to aldostrone. PHA type I, subdivided into isolated renal insensitivity to aldosterone of autosomal dominant inheritance and multiple target organ defect of autosomal recessive inheritance, and PHA type II show similar clinical manifestations except hypertension which is limited to type II. PHA type I is charaterized by hyponatremia, hyperkalemia, high plasma aldosterone and renin activity. Variable degrees, completely asymptomatic to severe fatal, of salt loosing manifestationsdehydration, hypotension, failure to thrive, and renal tubular acidosis usually start during infancy. Sodium loss not only from kidney but also from sweat gland, salivary gland and colon may occur in some cases. Recently we experienced two cases of PHA, a 27 days of age male newborn infant with charateristic clinical symptoms and typical laboratory manifestations of PHA, confirm diagnosed as PHA type I of isolated renal defect by pilocarpin iontophoresis showing normal sodium concentration in sweat gland, and his asymptomatic 6 year-old brother with the history of salt loosing symptoms treated until second year of life diagnosed as PHA type I by markedly elevated plasma aldosterone and renin activity. Brief review and related literatures were also presented.