Mutational analysis of the autoimmune regulator (AIRE) gene in sporadic autoimmune Addison's disease can reveal patients with unidentified autoimmune polyendocrine syndrome type I

OBJECTIVE: To investigate whether patients with Addison's disease and polyendocrine syndromes have undiagnosed autoimmune polyendocrine syndrome type I (APS I). MATERIALS AND METHODS: Forty patients with clinical manifestations resembling APS I and with autoantibodies typical of this condition were screened for Norwegian autoimmune regulator (AIRE) gene mutations. RESULTS: A 30-year old man who had developed Addison' s disease at the age of 12, but had no other components of APS I, was homozygous for the 1094-1106 deletion mutation in exon 8 of the AIRE gene, the most common mutation found in Norway. CONCLUSIONS: APS I patients with milder and atypical phenotypes are difficult to diagnose on clinical grounds. Autoantibody analysis and mutational analysis of AIRE may therefore be helpful modalities for identifying these individuals.