Stage 1 (increased plasma renin) for patients with APS-1 and Stage 2 (no response of cortisol to ACTH-test) for patients with APS-2/APS-4 were established as the points of no return in the progression to AAD.
By exploring the full set of 1800 candidate genes, we further identified common variation in the autoimmune regulator (AIRE) as a novel risk locus associated to sporadic AAD in our study.
Pathogenic variants in the autoimmune regulator (AIRE) gene are responsible for autoimmune polyendocrine syndrome type 1, of which AAD is a major disease component.
In addition, we analyzed five other family members out of three generations for the AIRE gene mutation and for polymorphisms in the cytotoxic T lymphocyte antigen 4 (CTLA4) gene region and lymphoid protein tyrosine phosphatase (PTPN22) gene, which are associated with the occurrence of sporadic autoimmune Addison's disease, type 1 diabetes mellitus, and generalized vitiligo.
Thus, the clinical diagnosis of APS1 is made in an individual who presents with at least two out of three cardinal symptoms, namely autoimmune Addison's disease, autoimmune hypoparathyroidism, and mucocutaneous candidiasis.
Mutational analysis of the autoimmune regulator (AIRE) gene in sporadic autoimmune Addison's disease can reveal patients with unidentified autoimmune polyendocrine syndrome type I.
In contrast, the mutant AIRE-1964del13 allele was carried in one each of the 576 (0.2%) control subjects and the 90 (1.1%) AAD subjects as a heterozygote (P = 0.254, not significant), suggesting that this common AIRE-1 gene abnormality does not have a major role in sporadic (non-APS1) AAD.
Autoimmune polyglandular syndrome type 1 [APS-1] comprises multiple organ-specific autoimmunities such as acquired hypoparathyroidism and autoimmune Addison's disease, and a predisposition to certain infections such as chronic mucocutaneous candidiasis.