"Dot-17 alpha-hydroxyprogesterone" radioimmunoassay for identification of congenital adrenal hyperplasia in young infants.

Using a simplified radioimmunoassay method for the determination of 17-hydroxyprogesterone (17-OHP) concentration in blood dried on filter paper seven untreated cases of congenital adrenal hyperplasia were identified among newborns and infants at risk for congenital adrenal hyperplasia (CAH) having ambiguous genitalia and/or failure to thrive with electrolyte disturbances. In three additional cases the diagnosis of congenital adrenal hyperplasia was confirmed by high 'dot-17-OHP' values even after glucocorticoid therapy had been started. Capillary blood samples taken in a local hospital on a filter paper routinely used for the screening of phenylketonuria can be sent by mail into a central laboratory for performing the analysis. Assays of 'dot-17-OHP' are clearly of diagnostic value in the C21-hydroxylase form of CAH and permit a rapid diagnosis of this condition in the newborn period.