RESUMEN
UNLABELLED: Multiple type I pseudohypoaldosteronism (PHA-I) is an autosomal recessive condition with multiple target-organ unresponsiveness to aldosterone, manifested early after birth with severe salt-wasting and hyperkalemia. Case 1. Female infant born at term after an uneventful pregnancy. One female sibling died in the first week of life with hyperkalemia. The diagnosis of multiple PHA-I resulted from a picture of dehydratation, hyperkalemia and hyponatremia with increased plasma renin activity (PRA), plasma aldosterone and sweat electrolytes. The treatment consisted of salt and sodium bicarbonate supplements, restricted potassium intake, cation exchange resins and high fluid intake. During first year she was hospitalized for severe salt-losing crises. At 7 years of age, she needs salt and sodium bicarbonate supplements and cation exchange resins. She has a normal growth and neurodevelopment. Case 2. Seven-day female newborn with consanguinity in maternal family. Pregnancy and delivery were uncomplicated. On admission she was severely dehydrated with hyponatremia, hyperkalemia, metabolic acidosis and elevated PRA, plasma aldosterone and sweat electrolytes. She remained hospitalized for six months and she was dependent on high amounts of salt and sodium bicarbonate supplements, fluid intake and cation exchange resins. Growth and neurodevelopment are normal. CONCLUSIONS: Multiple PHA-I may be suspected in a newborn with salt-loss and hyperkalemia without glucocorticoid defect. The frequent episodes of dehydratation during the first year of life require long hospitalization. The improvement with age make possible an ambulatory control after the first year of life.