Endocrine Abstracts

A 61-year-old gentleman, with a background of chronic schizophrenia, presented with hyponatraemia in 2008 and was diagnosed with Addison’s disease. He had two previous admissions with hyponatraemia in 2002 and 2006. During his first admission his hyponatraemia was attributed to volume depletion secondary to vomiting, and he responded to fluid resuscitation. On the second occasion, SIADH (syndrome of inappropriate antidiuretic hormone) was diagnosed secondary to antipsychotic medication. The patient was noted to be wheelchair-bound on both occasions but there was no formal neurological diagnosis made.

He was referred to Endocrinology out-patients in December 2008 for further management of his Addison’s disease. On examination he was noted to have a spastic paraparesis. There was no family history of adrenal insufficiency or neurological dysfunction.

Anti-adrenal antibodies were negative and very long chain fatty acid (VLCFA) levels were requested. VLCFAs showed increased C24 and C26 and C24/C22 and C26/C22 ratios consistent with a diagnosis of X-linked adrenoleukodystrophy; this was confirmed by subsequent genetic analysis with a missense mutation, c.761C>T in exon 1 of the ABCD1 gene. Family members have now been referred for genetic counselling and testing.

This case highlights the importance of proper evaluation of hyponatraemia, as well as testing for adrenoleukodystrophy in males with adrenal insufficiency with/without neurological findings.