Congenital adrenocortical unresponsiveness to ACTH (ACTH不応症) の2例

Congenital adrenocortical unresponsiveness to ACTH is characterized by hyperpigmentation, muscular weakness, and episodes of hypoglycemia, with lethargy or coma and convulsion, and without signs or symptoms of salt wasting. Endocrinological evaluation reveals low levels of serum and urinary glucocorticoids, elevated levels of plasma ACTH and unresponsiveness to exogenous ACTH. On the other hand, aldosterone secretion or excretion is normal and is elevated during a low sodium diet. We reported on two patients with this syndrome. Case A, a 4 year-old-girl, showed skin hyperpigmentation, hypoglycemia, convulsion and coma. She was tall wlth a marked advance of bone age. Case B, a 4 year-old-boy, showed skin hyperpigmentation, fatigability and muscular weakness. Both of them revealed low urinary excretion of THE, THF, cortolone, and beta-cortolone and low levels of plasma cortisol. The levels of urinary glucocorticoids and plasma cortisol did not respond to ACTH administration. During a low sodium diet, urinary aldosterone excretion was elevated, urinary sodium excretion ws decreased, and the patients were able to conserve sodium normally. We also summerized other reported cases and discussed the etiology of this syndrome.