Objective: X-linked adrenoleukodystrophy (X-ALD) is a rare, sometimes devastating disorder caused by-mainly inherited- mutations in the ABCD1 gene. Cerebral X-ALD can be prevented or modified if diagnosed presymptomatically. Mutation can lead to very long chain fatty acid (VLCFA) accumulation in adrenocortical cells, which can cause antibody negative primary Addisons disease (ANPAD). There are recommendations that all males affected by ANPAD should have VLCFA analysis. We aimed to identify whether all male patients with ANPAD received VLCFA testing.
Methods: All male patients with negative anti-adrenal antibodies testing and a subsequent diagnosis of ANPAD at Addenbrookes Hospital 20052014 were identified by i) Assessing all requests for adrenal antibodies, ii) Excluding all who tested positive, iii) Identifying those diagnosed with AD, iv) Excluding patients with secondary AD or with a clear cause for primary AD, e.g. adrenal haemorrhage, v) Checking whether those remaining had undergone VLCFA testing on the Addenbrookes results reporting system.
Results: 252/269 male patients tested negative for adrenal antibodies. 30/252 had been diagnosed with AD, of which 21 had ANPAD. 16/21 of the ANPAD cases were of unknown aetiology, only 8/16 underwent VLCFA analysis and none were found to have ALD.
Conclusions: There was a 50% failure rate for screening ANPAD patients with VLCFA in our centre. ALD-Life believes the figure is likely to be similar elsewhere. VLCFA is an economical, highly sensitive and specific test for detecting males carrying ABCD1 mutations and hence having family members at risk of cerebral ALD. We propose that the Society for Endocrinology should alert their members to offer VLCFA testing to all males with ANPAD.