A novel missense mutation of AIRE gene in a patient with autoimmune polyendocrinopathy,candidiasis and ectodermal dystrophy (APECED), accompanied with progressive muscular atrophy: case report and review of the literature in Japan

Autoimmune polyendocrinopathy, candidiasis, and ectodermal dystrophy (APECED) also known as autoimmune polyglandular syndrome type I, is a rare autosomal recessive disorder that results in several autoimmune diseases due to mutations in the AIRE (autoimmune regulator) gene. A 39-year-old female patient developed chronic mucocutaneous candidiasis at 3 yrs, idiopathic hypoparathyroidism at 11 yrs, chronic hepatitis at 23 yrs, Addison's disease and diabetes mellitus type I at 27 yrs. In addition, the patient developed progressive muscular atrophy of unknown etiology at the beginning of the third decade, and is bedridden at the present time. Her grandparents, parents, brother and daughter did not develop any features of APECED, but her father died of hepatoma. Direct sequencing of the AIRE gene revealed a novel missense mutation at exon 1 (R15C), which was identified to be of maternal origin. The other mutation was not found despite repeated sequencing of the whole coding regions. The R15C mutation was not detected in patients with idiopathic hypoparathyroidism (N= 10), idiopathic Addison's disease (N = 3), and normal subjects (N = 55). Although we could not analyze the father's gene, these results suggest that the patient is probably a compound heterozygote of the AIRE gene, in which the other abnormal allele could not be identified by the present analytical method. These data are compatible with the recent review that only one defective allele was detectable in some patients with clinically evident APECED. We found only six Japanese patients compatible with diagnosis of APECED, indicating that this autoimmune disease is extremely rare in our country.     

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.     

A novel AIRE mutation in an APECED patient with candidiasis, adrenal failure, hepatitis, diabetes mellitus and osteosclerosis.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disorder, which is characterized by an immune-mediated destruction of endocrine tissues, chronic candidiasis and ectodermal disorders. In contrast to many other autoimmune diseases, APECED is associated with mutations of a single gene, designated autoimmune regulator (AIRE). We describe an APECED patient with severe deformities of the tibia with radiological signs of metaphyseal dysplasia in addition to candidiasis, hepatitis, diabetes mellitus and adrenal failure. In this patient, we identified a novel AIRE mutation in association with the C322fsX372 mutation in exon 8, which is frequently detected in Caucasian patients. The frame shift mutation G263fsX377 in exon 6 results in a protein lacking both PHD zinc-finger domains similar to the R257 X mutation. This novel mutation was not found in 50 German controls.     

Autoimmune regulator (AIRE) gene on chromosome 21: implications for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) any more common manifestations of endocrine autoimmunity

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare, but well-defined monogenic disorder that is caused by mutations in the autoimmune regulator (AIRE) gene on chromosome 21q22.3. Patients most often suffer from loss of endocrine function in the parathyroid and adrenal glands but may also develop Type 1 diabetes, thyroid disease or hypogonadism. The disease may therefore serve as a model for sporadic endocrine autoimmunity and help to develop new screening and prevention methods. To date at least 46 mutations of AIRE have been identified in affected individuals. Little is known about heterozygosity states but patients with the more prevalent isolated autoimmune endocrinopathies such as Type 1 diabetes, Hashimoto's thyroiditis, Graves' or Addison's disease do not have any of the common mutations. This does not rule out AIRE to be affected either by so far unknown or regulatory variants. The recent characterization of AIRE knockout mice with similar immune pathological findings compared to the human setting will help to elucidate endocrine autoimmunity.     

Lupus-like panniculitis in a patient with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED).

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disorder, characterised by a loss of self-tolerance to endocrine tissues, chronic candidiasis and ectodermal disorders. APECED is associated with mutations of a single gene, designated autoimmune regulator (AIRE). We describe a 31-year-old APECED patient with non-traumatic, cutaneous ulcers on both forearms with features of a lupus-like panniculitis. On admission to the ICU in September 2001, the patient suffered from a ketoacidotic, hyperglycemic coma and adrenal crisis due to an Enterobacter-cloacae sepsis, originating from multiple, necrotising deep cutaneous ulcers. These ulcers spontaneously developed on both forearms, some of which were just emerging, full blown or healing with scars. Histological examination showed signs of a scarring panniculitis and vasculitis. Immunohistochemistry and direct immunofluorescence with characterisation of immunoglobulin and complement-factor binding pattern revealed features of a lupus-like panniculitis. Sequence analysis of all 14 exons of the AIRE gene revealed a R257 X mutation in exon 6 resulting in a nonsense mutation at codon 257 confirming the diagnosis of APECED. Oral treatment with 60 mg/day corticosteroids for two weeks led to complete resolution of all ulcers. In conclusion, mutations in the AIRE gene may provide the genetic background against which additional factors can initiate an autoimmune process. Here, autoimmune panniculitis appears to be an associated feature of the APECED syndrome. Our findings support the use of immunosuppressive therapy for autoimmune disease components of the APECED syndrome.     

Recurrent herpes simplex virus infection in a patient with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy associated with L29P and IVS9-1G>C compound heterozygous autoimmune regulator gene mutations

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) has characteristic clinical features with organ-specific autoimmune polyendocrine diseases and candidiasis, caused by the mutations of autoimmune regulator (AIRE) gene. Although almost all patients are complicated with mucocutaneous candidiasis, no apparent susceptibility to other infections has yet been reported. We herein report that a patient with APECED suffered from recurrent herpes simplex virus type 1 (HSV-1) infection after severe primary herpetic stomatitis, associated with sequential HSV-1 isolates of the same genomic profile, consistent with endogeneous recurrence. Thus, not only candidiasis but also HSV infection should receive more attention in patients with APECED, with treatment being administered accordingly.     

Autoimmune polyendocrine syndrome type 1: case report and review of literature

Autoimmune polyendocrine syndrome type 1 (APECED) is a rare autosomal recessive disorder characterized by autoimmune multiorgan attack. The disease is caused by mutations in the autoimmune regulator gene (AIRE), resulting in defective AIRE protein, which is essential for selftolerance. Clinical manifestations are widely variable. Although the classic triad is composed by mucocutaneous candidiasis, hypoparathyroidism and adrenal failure, many other components may develop. Treatment is based on supplementation of the various deficiencies, and patients require regular follow-up throughout their lifespan. This article describes the case of a patient with the disease, and reviews literature data on the epidemiology, clinical course, immunogenetic aspects, diagnosis and treatment of the syndrome.     

Novel mutations of the autoimmune regulator gene in two siblings with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is the first multiple autoimmune disease that has been shown to be caused by mutations of a single gene named autoimmune regulator (AIRE). Fourteen different mutations of the AIRE gene have been identified in 61 patients from 55 families with APECED. However, there has been no report documenting AIRE gene mutations in the Asian population. We report on 2 siblings with variable manifestations of APECED who were born to a Japanese mother and a Korean father. The 11yr-old girl had intractable thrush and ungual candidiasis, hypoparathyroidism, and occipital alopecia. The 9-yr-old boy had mild ungual candidiasis alone. Direct sequencing revealed novel frameshift mutations of the AIRE gene: an insertion of a cytosine at nucleotide 29635 at the exon 10 (29635insC), which should lead to a premature termination at the codon 371, producing a truncated protein missing the second plant homeodomain-type zinc finger motif and the third LXXLL motif, and a deletion of a guanine at nucleotide 33031 at the exon 13 (33031delG), which should result in a premature termination at the codon 520, yielding a truncated protein missing the third LXXLL motif. The mother was heterozygous for 29635insC, and the father was heterozygous for 33031delG. The frameshift mutations were undetected in 40 alleles of 20 Japanese control subjects. The results imply that the C-terminus of AIRE protein including the third LXXLL motif plays a critical role in the development of APECED, and that the phenotypic spectrum can vary between siblings with the same mutations.     

Adrenal autoimmunity: results and developments.

Autoimmune Addison's disease (autoimmune adrenalitis) often occurs in autoimmune polyendocrinopathy syndromes APS1 (APECED) and APS2. Although the genetic background and etiology of the two syndromes is remarkably different, they both result in a similar autoimmune destruction of the adrenal cortex. Recently, the defective gene in APS1, AIRE (autoimmune regulator) was identified, whereas in APS2, the major genetic factor remains to be found in the human major histocompatibility complex haplotype (HLA) region. In addition to the genetic factors, the recent findings in genetics and immunity leading to the pathogenesis of adrenal autoimmunity in polyendocrinopathy syndromes are discussed.     

The genetics of autoimmune polyendocrine syndrome type II.

A series of autoimmune disorders, often Addison's disease, type 1 diabetes mellitus, and thyroid autoimmunity, frequently occurs together in patients with the autoimmune polyendocrine syndrome type II (APS-II). The highest risk HLA genotype for Addison's disease, either as a single disease or in APS-II patients, consists of the genotype DR3/4, DQ2/DQ8 with DRB1*0404. As many as 30% of patients with Addison's disease have this genotype versus less than 0.5% of controls. An additional and important associated locus within the HLA region is the class I related gene, MIC-A. Patients who develop Addison's disease often have a delayed diagnosis and may die from Addisonian crisis; therefore, improved genetic testing combined with testing for 21-hydroxylase autoantibodies might allow the identification of relatively high-risk populations (greater than 1 in 200 defined genetic risk compared with 1 in 10,000 population risk).     

Interferon autoantibodies associated with AIRE deficiency decrease the expression of IFN-stimulated genes

Neutralizing autoantibodies to type I, but not type II, interferons (IFNs) are found at high titers in almost every patient with autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), a disease caused by AIRE gene mutations that lead to defects in thymic T-cell selection. Combining genome-wide expression array with real time RT-PCR assays, we here demonstrate that antibodies against IFN-alpha cause highly significant down-regulation of interferon-stimulated gene expression in cells from APECED patients' blood by blocking their highly dilute endogenous IFNs. This down-regulation was lost progressively as these APECED cells matured in cultures without neutralizing autoantibodies. Most interestingly, a rare APECED patient with autoantibodies to IFN-omega but not IFN-alpha showed a marked increase in expression of the same interferon-stimulated genes. We also report unexpected increases in serum CXCL10 levels in APECED. Our results argue that the breakdown of tolerance to IFNs in AIRE deficiency is associated with impaired responses to them in thymus, and highlight APECED as another autoimmune disease with associated dysregulation of IFN activity.     

Autoimmune regulator-1 messenger ribonucleic acid analysis in a novel intronic mutation and two additional novel AIRE gene mutations in a cohort of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy patients

CONTEXT: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disease associated with mutations in the AIRE gene. OBJECTIVE: Our objective was to investigate clinical and mutational characteristics of 12 Slovenian patients from 10 families with APECED. METHODS: Direct sequencing, restriction fragment length polymorphism, and amplification refractory mutation system analyses were used to identify AIRE gene mutations. Autoimmune regulator (AIRE)-1 mRNA analysis was used to confirm pathogenicity of the intronic mutation. RESULTS: The prevalence of APECED in Slovenian population was estimated to be 1 in 43,000, which is significantly higher compared with the neighboring populations. Three novel mutations were identified among six different mutations detected in the AIRE gene. The first novel mutation was an intronic mutation (653-7_-5delCTC) affecting proper splicing by using a nearby new acceptor splice site as demonstrated by AIRE-1 mRNA analyses. The second and third novel mutations were frame-shift mutations located in exon 5 (540delG) and exon 9 (1064-1068dupCCCGG), both leading to premature truncation of the AIRE protein. The Finnish R257X mutation was the most frequent AIRE gene mutation in Slovenian patients with APECED (16 of 24 alleles). CONCLUSIONS: Three novel AIRE gene mutations were identified. For the first time, a novel intronic mutation was investigated on the mRNA level in APECED. This could be particularly important for APECED patients where no or only heterozygous mutation on the genomic DNA level is detected.     

A heterozygous deletion of the autoimmune regulator (AIRE1) gene, autoimmune thyroid disease, and type 1 diabetes: no evidence for association

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare monogenic autoimmune disease with endocrine components including type 1 diabetes, adrenal failure, and thyroid dysfunction, with major autoantibodies directed against adrenal, pancreas, and thyroid tissue. A 13-bp deletion in exon 8 of the autoimmune regulator (AIRE1) gene on chromosome 21q22.3 accounts for more than 70% of mutant alleles in United Kingdom subjects with APECED. To determine whether this polymorphism contributes to disease susceptibility in subjects with autoimmune disease in general, we screened 302 patients with Graves' disease, 154 patients with autoimmune hypothyroidism, 235 patients with type 1 diabetes, and 318 control subjects for the 13-bp deletion of the AIRE1 gene. The mutation was present in only 1 (0.33%) patient with Graves' disease, 1 patient with autoimmune hypothyroidism (0.6%), and 1 (0.315) of the control subjects. No patients with type 1 diabetes were found to carry the mutation. We conclude, therefore, that the 13-bp deletion of the AIRE1 gene is not a susceptibility locus for the more common autoimmune endocrinopathies in the United Kingdom.     

Mutational analysis of the autoimmune regulator (AIRE) gene in sporadic autoimmune Addison's disease can reveal patients with unidentified autoimmune polyendocrine syndrome type I

OBJECTIVE: To investigate whether patients with Addison's disease and polyendocrine syndromes have undiagnosed autoimmune polyendocrine syndrome type I (APS I). MATERIALS AND METHODS: Forty patients with clinical manifestations resembling APS I and with autoantibodies typical of this condition were screened for Norwegian autoimmune regulator (AIRE) gene mutations. RESULTS: A 30-year old man who had developed Addison' s disease at the age of 12, but had no other components of APS I, was homozygous for the 1094-1106 deletion mutation in exon 8 of the AIRE gene, the most common mutation found in Norway. CONCLUSIONS: APS I patients with milder and atypical phenotypes are difficult to diagnose on clinical grounds. Autoantibody analysis and mutational analysis of AIRE may therefore be helpful modalities for identifying these individuals.     

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome: time to review diagnostic criteria?

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an autosomal-recessive syndrome defined by two of the following conditions: chronic mucocutaneous candidiasis, hypoparathyroidism, or Addison's disease. Other autoimmune conditions may be associated, such as hypothyroidism, hypogonadism, insulin-dependent diabetes mellitus, chronic active hepatitis, pernicious anemia, vitiligo, alopecia, biliary cirrhosis, and ectodermal dysplasia. APECED is caused by mutations in the autoimmune regulator gene, mapping to 21q22.3. We report on three patients whose clinical and molecular features challenge the currently used diagnostic criteria for APECED. AR presented at 15 yr of age with a history of recurrent infections and mucocutaneous candidiasis. He is now 21 yr old, and no other signs or symptoms of APECED have appeared to date. DR presented at 7 yr of age with hypocalcemia and a prolonged Q-T interval on the electrocardiogram. He also had minor facial dysmorphisms and mild mental retardation. Serum calcium levels were low, PTH levels were undetectable, and hypoparathyroidism was therefore diagnosed. All other biochemical, immunological, and endocrinological tests were normal. DR is now 8 yr old with no other signs or symptoms of APECED. ST presented at 14 yr of age for alopecia aerata and pitted nail dystrophy and goiter. Thyroid function was normal in the presence of thyroid-specific antibodies. No other signs or symptoms of APECED have appeared to date. Genetic analysis revealed a typical mutation (R257X) on a single allele in both AP and DR; in ST, heterozygosity for a novel mutation (V484M) involving one of the zinc fingers of the plant homeodomain of the protein was found. The finding of a typical APECED mutation in two patients presenting with one isolated major clinical APECED feature and of a novel mutation in a patient presenting with atypical features of APECED onset suggests that the time might have come for updating the diagnostic criteria of this syndrome.     

Linkage disequilibrium between HLA class II region and autoimmune hepatitis in pediatric patients

BACKGROUND/AIMS: Susceptibility HLA class II alleles associated with autoimmune hepatitis (AIH) were only described in case-control studies. METHODS: The transmission/disequilibrium test was used in 50 simplex families with AIH, to determine if affected offspring received the disease-associated allele more frequently than its alternate. HLA-DRB1 and DQB1 allele genotyping and autoimmune regulator (AIRE) polymorphisms located in exons 6, 8 and 10 were investigated by PCR-based methods. RESULTS: HLA-DRB1*03 allele was significantly transmitted from heterozygous parent to affected offspring (81.5%) with type 1 AIH compared to random expected frequency (50.0%; P=0.004) or to unaffected offspring (42.8%; P=0.03). HLA-DRB1*1301 allele showed an excess transmission to affected children (100%) than expected frequency (P<0.0001) or unaffected offspring (P=0.001). The transmission of DQB1*201 or DQB1*0603 alleles showed significant deviation in patients compared to random frequencies: (84.8%; P<0.0001 for DQB1*0201 or 100%; P<0.0001 for DQB1*0603). HLA-DQB1*0201 showed a strong association with type 2 AIH in children (100.0%, P=0.0005). CONCLUSIONS: HLA-DRB1 gene is the major genetic determinant in HLA class II region for children with type 1 AIH. Type 2 AIH is associated with the HLA-DQB1gene. Finally, AIRE gene abnormality does not contribute to the development of isolated AIH.