X-linked adrenoleukodystrophy: are signs of hypogonadism always due to testicular failure?

We present the clinical and hormonal findings of a young male with X-linked adrenoleukodystrophy (X-ALD), with special emphasis on the biochemical and clinical pattern of hypogonadism. A patient, with primary adrenal insufficiency since the age of 5 years, developed progressive neurological symptoms at the age of 29. Diagnosis of X-ALD was established by elevated serum very long chain fatty acids (VLCFAs) and genetic testing. His sexual body hair was sparse. Hormonal investigations revealed normal testosterone and inappropriately elevated LH levels. Androgen receptor gene analysis was negative for mutations or polymorphic variants associated with decreased receptor activity. Signs of hypogonadism in patients with confirmed X-ALD are not exclusively due to primary testicular failure. Tissue specific androgen resistance represents an alternative possibility. Since no loss-of-function mutations were detected in the androgen receptor, it is speculated that the patient's androgen resistance could be part of a functional defect mediated through VLCFA accumulation at the testosterone receptor and/or post-receptor levels.