Familial Cushing's syndrome. Micronodular adrenocortical dysplasia.

Primary micronodular adrenocortical dysplasia is a rare cause of Cushing's syndrome. Recently, a familial occurrence of this disease has been recognized. We describe two sisters with Cushing's syndrome in a family of four children. Adrenal autonomy was demonstrated and pathological examination after bilateral adrenalectomy at the ages of 14 and 30 years, respectively, revealed micronodular adrenocortical dysplasia. Malformations associated with the Carney variant of this disease were not detected in our patients. The two affected siblings had HLA types A1, B8, and DR3, which are seen in many autoimmune diseases. The mother and brother had similar HLA types and showed incomplete dexamethasone suppression. However, they did not have clinical manifestations of Cushing's syndrome. Another sister and her daughter had different HLA typing and had no detectable abnormalities of cortisol secretion.