Molecular background and genotype-phenotype correlation in autoimmune-polyendocrinopathy-candidiasis-ectodermal-distrophy patients from Campania and in their relatives.

ABSTRACT

BACKGROUND: Autoimmune-polyendocrinopathy-candidiasis- ectodermal-distrophy (APECED) is a recessive disease, caused by mutations in the AutoImmune REgulator (AIRE) gene. Different mutations are peculiar of particular populations. In Italy, 3 hot spots areas where APECED shows an increased prevalence, have been identified in Sardinia, Apulia, and in the Venetian region. AIM: In this study, we analyzed AIRE mutations and genotype-phenotype correlation in APECED patients originating from Campania and in their relatives. PATIENTS AND METHODS: In 6 patients affected with APECED clinical findings, genetic analysis of AIRE, and APECED-related autoantibodies were performed. RESULTS: All patients carried at least 1 mutation on exon 1 or on splice-site flanking exon 1. Two siblings carried a complex homozygous mutation [IVS1 + 1G>C; IVS1 + 5delG] on intron 1; 2 patients were compound heterozygous for [T16M]+[W78R] (exons 1+2); 1 patient was compound heterozygous for [A21V]+[C322fs] (exons 1+8) and another was homozygous for [T16M]+[T16M] on exon 1. Expression of the disease showed wide variability while circulating autoantibodies paralleled to phenotype in each patient. Analysis of relatives allowed the identification of 8 heterozygotes. None of heterozygous subjects presented major findings of APECED. CONCLUSIONS: Mutations localized on exon 1 and the region flanking exon 1 are common in APECED patients originating from Campania. Genotype-phenotype correlation failed to reveal a relationship between detected mutations and clinical expression. Mutations in heterozygosis in AIRE gene are not associated to major findings of APECED.