Hyporeninemic hypoaldosteronism in infancy: a familial disease.

Hyporeninemic hypoaldosteronism was found in two male siblings with urinary salt wasting and low plasma sodium levels. The eldest, aged 1 yr, had growth retardation, with hyponatremia and normal plasma potassium levels. The second, aged 2 months, had low plasma sodium and high plasma potassium levels. Both were severely and repeatedly hypoaldosteronemic. Primary adrenal deficiency was excluded by ACTH testing, which showed a good aldosterone rise and normal responses of other steroids. Both children had low PRA compared to that in age-matched normal subjects. The eldest sibling also had decreased total renin, low inactive to total renin ratio, and a subnormal level of angiotensinogen. The father had low plasma angiotensinogen levels. Congenital deficiency of renin activity and/or angiotensinogen production is suggested as the primary abnormality.