Endocrine Abstracts

X-linked adrenoleukodystrophy (ALD) is a rare condition affecting the nervous system and adrenal cortex that typically presents in childhood. It results from mutations in the ABCD1 gene. We describe two cases of ALD presenting with hypoadrenalism in adulthood.

A 20 year old man presented with persistent vomiting. He was pigmented, blood pressure was 100/60 mmHg, and neurological examination was normal. Investigations showed serum sodium 125 mmol/L, urea 17.5 mmol/L and creatinine 212 umol/L. A short synacthen test confirmed hypoadrenalism (peak serum cortisol 74 nmol/L), adrenal antibodies were negative. Serum very long chain fatty acid (VLCFA) analysis showed elevated C24/C22 and C26/C22 ratios. MRI brain scan showed a subtle area of high signal change in the occipital white matter. Nerve conduction studies were normal. Genetic analysis showed exon 1 deletion in the ABCD1 gene, confirming ALD. He was treated with hydrocortisone and fludrocortisone and has started prophylactic Lorenzo’s oil.

A 64 year old man presented with dizziness. His grandson had confirmed ALD. He was pigmented but otherwise examination was normal. Serum sodium was 130 mmol/L. A short synacthen test confirmed hypoadrenalism (peak serum cortisol 55 nmol/L), adrenal antibodies were negative. VLCFA analysis yielded raised C24/C22 and C26/C22 ratios. Genetic analysis showed mutation in exon 1 of the ABCD1 gene confirming ALD. Nerve conduction studies were normal. He received hydrocortisone replacement.

ALD is commonly associated with severe progressive neurological impairment. In adulthood it can present with hypoadrenalism and the diagnosis should certainly be considered in young adult males. Our second case shows that the condition can present at an advanced age. It is important to make the diagnosis of ALD in adults as other family members may be severely affected at a young age.