Endocrine Abstracts

Introduction: X-linked adrenoleukodystrophy (X-ALD) is an important cause of primary adrenocortical insufficiency (PAI) in men. It’s characterized by impairment in peroxisomal degradation of very-long-chain-fatty-acids (VLCFA), leading to its accumulation on central nervous system, adrenal cortex and testes.

Adrenomyeloneuropathy, the most common phenotype of X-ALD, coexists with PAI in up to 70% cases.

Case report: A 28-year-old previously healthy male, with acute impairment of muscular strength, was referred to Neurology’s Department. Neurologic examination revealed a spastic paraparesis, generalized hyperreflexia, distal hypoesthesia and ataxic gait.

Cranial MRI displayed contrast enhancement at right internal capsule, suggesting active demyelination.

His clinical condition grew worse along the following 10 years and he further developed spastic tetraparesis, urinary incontinence and behavioural changes. Meanwhile, his nephew was diagnosed as having X-ALD. The patient’s plasmatic VLCFA levels were assessed, he was classified with the same diagnosis and then referred to Endocrinology’s Department.

He was normotense and without hyperpigmentation. Plasmatic glucose, sodium and potassium levels were normal. The tetracosactrin-stimulation-test showed high basal level of ACTH (360 pg/ml; RR:9–52) and a subnormal cortisol response (basal-23.2; 60’ after-22.7 μg/dl). The total testosterone was 6.4 ng/ml (RR:2.7–11), renin 14 μU/ml (RR:7–76) and aldosterone 21 pg/ml (RR:40–310).

Later, at the age of 39, diabetes’ diagnosis was settled and treated with insulin. He presented negative diabetes-specific-autoantibodies and a good C-peptide reserve (glucagon test: basal C-peptide-2.4; 6’ after-6.8 ng/ml).

He has a 5-cm thyroid nodule (whose FNA result was ‘benign’), in waiting for surgery.

Conclusion: X-ALD is a clinically heterogeneous disease.

The reported case was diagnosed due to advanced neurologic disease; a low adrenal reserve was also found.

In conclusion, adrenal reserve must be regularly assessed in X-ALD in order to early diagnose PAI and avoid an adrenal crisis triggered by an eventual stress. Likewise, an early diagnosis of X-ALD in PAI might prevent progression to neurologic disability.