Autoimmune Polyglandular Syndrome Type 1 in Russian Patients: Clinical Variants and Autoimmune Regulator Mutations

Abstract

Background: Autoimmune polyglandular syndrome type 1 (APS-1) (OMIM 240300) is a rare autosomal recessive disorder associated with three major manifestations: chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency. There are, however, multiple minor components of APS-1 that induce significant phenotype variability. Subsequently, the diagnosis of APS-1 during early stages is often challenging. Aim: We aimed to provide clinical and mutational data for a large number of APS-1 patients in the Russian population. Methods: We analyzed clinical variations and component prevalence in APS-1 patients. DNA screening for autoimmune regulator (AIRE) gene mutations was performed in established APS-1 patients and in patients with the single components of chronic mucocutaneous candidiasis, hypoparathyroidism, adrenal insufficiency, or alopecia. Results: We identified 46 patients from 42 families with APS-1. Eighteen different components were present in the patients, including very rare conditions – bone dysplasia and retinitis pigmentosa. We identified 10 different mutations, 3 of which were novel (M1T, E298K, c1053_1060del). The common Finnish mutation, R257X, was the most frequent in our population, present in 64/92 (70%) of the alleles. Conclusion: We found that the R257X AIRE mutation is common in Russian APS-1 patients. The majority of children with hypoparathyroidism and chronic mucocutaneous candidiasis were carriers of the AIRE mutations.