[Pseudohypoaldosteronism--renal salt loss syndrome. Therapy and course exemplified by 2 siblings]

In 2 sibs pseudohypoaldosteronism was diagnosed by measurements of high serum aldosterone and elevated plasma renin activity. During their first week of life the first born girl, phenotypically normal, went through a severe salt-losing crisis with hyponatremia and hyperkalemia. Steroids given because of suspected congenital adrenal hyperplasia had no effect. High parenteral and later oral substitution of sodium normalized the serum electrolytes. The younger brother had milder symptoms. His salt-losing crisis developing during the first week of life was treated immediately with salt substitution. Both children developed normally with high oral sodium chloride supplementation, as regulated by the parents, using daily body weight measurements. Both children frequently suffer salt-losing crises, generally preceded by simple upper respiratory tract infections, which have to be treated in the hospital by infusion with a hyperosmolar sodium chloride solution.