A salt‐wasting syndrome associated with high plasma renin activity and inappropriately low aldosterone levels was observed among eight Jewish families from Iran. Aldosterone deficiency was due to an inborn error selectively involving the terminal portion of the biosynthetic pathway and characterized by an enzymic block in the conversion of 18‐hydroxycorticosterone to aldosterone. The analysis of the eight pedigrees, including 12 affected children, shows a high coefficient of inbreeding. Genetic analysis, by two independent methods, strongly suggests an autosomal recessive mode of transmission of the syndr