Diagnosis and Nomenclature of the Disorders of the Terminal Portion of the Aldosterone Biosynthetic Pathway

The abnormal steroid pattern in an inborn error in aldosterone biosynthesis consists of overproduction of glomerulosa zone 18-hydroxycorticosterone relative to aldosterone. The normal values for the excretory ratio of the major urniary metabolites of these two steroids are presented to provide a basis for the diagnosis of abnormalities in their ratio. The production of glomerulosa zone 18-hydroxycorticosterone relative to aldosterone is remarkably constant over a large range of absolute values, except in the disorder involving the terminal portion of the aldosterone biosynthetic pathway for which the term corticosterone methyl oxidase defect, Type 2, is suggested.