Identification of two novel mutations in the first Sicilian APECED patient with no R203X mutation in AIRE gene and review of Italian APECED genotypes.

UNLABELLED: Aims of the present study are: 1) to report an additional Sicilian patient with autoimmune polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED), whose genotypic features are original, in that she is the first APECED patient with three coexisting mutations of Autoimmune Regulator (AIRE) gene, two of which had never been reported to date; 2) to review the genotypic epidemiology of APECED in Italy, in order to underline the great genetic heterogeneity of this disorder in Italian patients. Both the novel mutations of our new patient, named S107C and Q108fs respectively, were detected on exon 3 and were inherited by the mother, whereas the third one (T16M) was inherited by the father. Phenotypically, the present case is quite characteristic, in that she exhibited a classical clinical picture, with no original features. CONCLUSIONS: a) this is the seventh Sicilian APECED patient identified to date, and the first one with no R203X mutation; b) our data confirm that distribution of mutations may considerably vary according to different geographical distribution, within the same country, thus suggesting a potential founder effect.

AIRE gene mutations and autoantibodies to interferon omega in patients with chronic hypoparathyroidism without APECED.

OBJECTIVE: To assess autoimmune regulator (AIRE) gene mutations, class II HLA haplotypes, and organ- or non-organ-specific autoantibodies in patients with chronic hypoparathyroidism (CH) without associated Addison's disease (AD) or chronic candidiasis (CC). DESIGN, PATIENTS AND MEASUREMENTS: Twenty-four patients who had CH without AD or CC were included in the study. AIRE gene mutations in all 14 exons were studied using PCR in 24 patients, 105 healthy controls and 15 first-degree relatives of CH patients with AIRE mutations. Human leucocyte antigens (HLA) were determined for all 24 patients and 105 healthy controls. Autoantibodies to a range of antigens including NACHT leucine-rich-repeat protein-5 (NALP5) and interferon omega (IFNω) were tested in all 24 patients. RESULTS: AIRE gene mutations were found in 6 of 24 (25%) patients, all females, and this was significantly higher (P < 0·001) compared with AIRE mutations found in healthy controls (2/105). Three patients (12·5%) had homozygous AIRE mutations characteristic of Autoimmune-Poly-Endocrinopathy-Candidiasis-Ectodermal-Dystrophy and all three were also positive for IFNω-autoantibodies. Three patients (12·5%) had heterozygous AIRE mutations; two of these were novel mutations. One of the patients with heterozygous AIRE mutations was positive for both NACHT leucine-rich-repeat protein 5 and IFNω autoantibodies. Heterozygous AIRE mutations were found in 10 of 15 first-degree relatives of CH patients with AIRE mutations, although none was affected by CH. Class II HLA haplotypes were not statistically different in patients with CH compared to healthy controls. CONCLUSIONS: Analysis of AIRE gene mutations together with serum autoantibody profile should be helpful in the assessment of patients with CH, in particular young women with associated autoimmune diseases.

Evaluation of the autoimmune regulator (AIRE) gene mutations in a cohort of Italian patients with autoimmune-polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED) and in their relatives.

OBJECTIVE: Autoimmune-polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED) is a rare syndrome characterized by chronic candidiasis, chronic hypoparathyroidism and Addison's disease. APECED has been associated with mutations in autoimmune regulator (AIRE) gene. Our aim is to perform a genetic analysis of the AIRE gene in Italian APECED patients and in their relatives. Design AIRE mutations were determined by DNA sequencing in all subjects. Patients were tested for clinical autoimmune or non-autoimmune diseases, or for organ and non-organ specific autoantibodies. PATIENTS: A total of 24 Italian patients with APECED (15 from the Venetian region, 2 from Southern-Tyrol, 4 from Apulia, 3 from Sicily), 25 relatives and 116 controls were studied. RESULTS: Ten out of the 15 Venetian patients (66%) were homozygous for R257X or compound heterozygous with 1094-1106del13. One patient was homozygous for 1094-1106del13 and another for R139X. A novel mutation (1032-1033delGT) in combination with 1094-1106del13 was identified in one patient. No mutations were found in two cases. Two patients from Southern Tyrol were homozygous for R257X and for 1094-1106del13bp. All patients from Apulia were homozygous or heterozygous for W78R combined with Q358X. The patients from Sicily were homozygous for R203X or compound heterozygous with R257X. The analysis of the genotype-phenotype revealed that patients carrying 1094-1106del13 at the onset of Addison's disease were significantly older than those carrying other mutations. The genetic study of 25 relatives identified 20 heterozygous subjects. They suffered from various autoimmune and non-autoimmune diseases but no major disease of APECED was found. CONCLUSION: These data demonstrate the great genetic heterogeneity for the AIRE mutations in Italian APECED patients, and that the heterozygosity for AIRE mutations do not produce APECED.

Sicilian family with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) and lethal lung disease in one of the affected brothers.

INTRODUCTION: We report the clinical and immunological features of the autoimmune regulator gene (AIRE) in two Sicilian brothers with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). They were compound heterozygotes with R203X/R257X. Both had oral candidiasis since the first year of life and later developed hypoparathyroidism and Addison disease. The elder brother had experienced recurrent lower respiratory infections since 5 years of age and over the years developed severe obstructive lung disease with bronchiectasis, which led to death at 18 years of age. Both brothers had circulating autoantibodies against tryptophan hydroxylase and serotonin-producing cells were absent in the duodenal mucosa. This was associated with intestinal dysfunction in only the elder brother. CONCLUSION: (1) In the first Sicilian family with APECED reported up to now we found a heterozygous mutation that had been previously reported only once. (2) In the older brother of this family we observed a severe and lethal lung disease; this case adds to a growing literature describing this association between APECED and respiratory illnesses. (3) Tryptophan hydroxylase antibodies might be hypothesized to be the marker of an autoimmune gastrointestinal illness possibly associated with APECED.