Distinct clinical phenotype and immunoreactivity in Japanese siblings with autoimmune polyglandular syndrome type 1 (APS-1) associated with compound heterozygous novel AIRE gene mutations

We herein report on two Japanese siblings with autoimmune polyglandular syndrome type 1 (APS-1). The brother, who expressed a characteristic phenotype of APS-1, had developed severe mucocutaneous candidiasis in early infancy and thereafter developed hypoparathyroidism and Addison's disease, along with a severe deterioration of his immunologic function. In contrast, the 44-year-old sister, who showed a noncharacteristic phenotype of APS-1, developed insulin-dependent diabetes with high anti-glutamic acid decarboxylase antibody, mild nail candidiasis, and autoimmune hepatitis with intact immunoreactivity. She had three susceptible human leukocyte antigen (HLA) loci for type 1 autoimmune diabetes. The expression of T cell receptor (TCR)Vβ5.1 increased in both patients, while the brother showed a widely suppressed expression of many TCRVβ families. Both individuals possessed compound heterozygous novel autoimmune regulator (AIRE) gene mutations (L29P and IVS9-1G>C). The same AIRE gene mutations can thus be associated with characteristic and noncharacteristic phenotypes of APS-1, and HLA may possibly influence the phenotype of APS-1.