Early diagnosis of 11 beta-hydroxylase deficiency in two siblings confirmed by analysis of a novel steroid metabolite in newborn urine.

Plasma and urinary steroid measurements are reported in 2 normotensive newborn female siblings with virilized external genitalia due to 11 beta-hydroxylase deficiency. Plasma 11-deoxycortisol concentrations were markedly elevated whereas 17OH-progesterone concentrations were not raised. Plasma renin activity was suppressed, but increased to levels characteristic of infancy within 4 weeks of treatment. The enzyme defect was confirmed by measurement of increased urinary excretion of tetrahydro-11-deoxycortisol. A more polar steroid metabolite, 6 alpha-hydroxytetrahydro-11-deoxycortisol was also determined by gas chromatographic and mass spectrometric analysis. Analysis of metabolites in urine is an additional specific marker to plasma 11-deoxycortisol measurement for the diagnosis of 11 beta-hydroxylase deficiency in early infancy.