Cytochrome P450 oxidoreductase deficiency with Antley-Bixler syndrome: steroidogenic capacities.

For patients with cytochrome P450 oxidoreductase deficiency (PORD), steroid replacement is recommended at times of stress. However, it is unknown how hormones respond to actual physical stress in these patients. We report a female infant with PORD accompanied by the Antley-Bixler syndrome phenotype. Her urinary steroid profile revealed defective CYP17A1 and CYP21A2 activities, and an adrenocorticotropin (ACTH) stimulation test showed potential adrenal insufficiency. Hormonal responses to actual physical stress were as follows: Vigorous crying during blood sampling rarely affected the serum cortisol level. Acute viral gastroenteritis led to marked increases in blood ACTH and 17alpha-hydroxyprogesterone levels in proportion to the severity of the illness. The serum cortisol level also responded to this stress, but the response might have been blunted. Regarding peri-operative steroid replacement, intravenous hydrocortisone administration even at a dose of 6 mg/kg, which is lower than that recommended for congenital adrenal hyperplasia in Japan, proved to be excessive.