Four cases of adrenoleukodystrophy (ALD) and one case of adrenomyeloneuropathy (AMN) have developed in a kindred over three generations demonstrating that AMN is a clinical variant of ALD. Pituitary-adrenal function studies were performed in 10 family members, including two affected males and four females identified as carriers of ALD/AMN. No pituitary-adrenal abnormality was found in the carriers. However, basal morning plasma adrenocorticotropic hormone (ACTH) levels were markedly elevated in the two males with ALD and AMN, despite the fact that they had no clinical signs of adrenal insufficiency and that morning plasma cortisol levels and their response to maximal exogenous ACTH stimulation appeared to be normal. In addition, the integrated 24-hour response to the administration were also subnormal in these two cases. Thus, people with ALD and AMN may have subclinical partial adrenocrotical insufficiency. No other endocrinologic dysfunction was identified.