Novel compound heterozygous AIRE mutations in a Japanese patient with APECED

Exploring Chronic Hypocalcemia: Insights into Autoimmune Polyglandular Syndrome Type 1-A Case Study and Literature Review

Hypocalcemia is a common occurrence in pediatric patients, attributed to various causes and presenting with diverse clinical manifestations. A prompt evaluation is necessary to determine its underlying cause, whether it presents acutely or chronically, and to tailor treatment based on its severity. Among the potential causes of chronic hypocalcemia, primary hypoparathyroidism stands out. The case of a seven-year-old male patient with hypocalcemia reported in this article serves as an illustration, wherein targeted next-generation sequencing revealed a homozygous p.R257X mutation in the AIRE gene, indicative of autoimmune polyendocrine syndrome type 1 (APS-1). It poses challenges due to its multisystemic nature and involvement of specific autoantibodies, often leading to underdiagnosis, owing to its rarity, varied manifestations, and incomplete penetrance. A comprehensive review of the APS-1 literature was conducted to provide insights into the clinical manifestations, genetic spectrum, potential immunological mechanisms, and current medical strategies. Additionally, the recognition of AIRE gene mutations is crucial for facilitating genetic diagnosis, prognosis, and potential treatment strategies for APS-1. The management of such cases involves individualized approaches to treatment, regular monitoring, medication adjustments, and the early identification of associated conditions.

Autoimmune polyendocrine syndrome type 1: an Italian survey on 158 patients

BACKGROUND

Autoimmune Polyglandular Syndrome type 1 (APS-1) is a rare recessive inherited disease, caused by AutoImmune Regulator (AIRE) gene mutations and characterized by three major manifestations: chronic mucocutaneous candidiasis (CMC), chronic hypoparathyroidism (CH) and Addison's disease (AD).

METHODS

Autoimmune conditions and associated autoantibodies (Abs) were analyzed in 158 Italian patients (103 females and 55 males; F/M 1.9/1) at the onset and during a follow-up of 23.7 ± 15.1 years. AIRE mutations were determined.

RESULTS

The prevalence of APS-1 was 2.6 cases/million (range 0.5-17 in different regions). At the onset 93% of patients presented with one or more components of the classical triad and 7% with other components. At the end of follow-up, 86.1% had CH, 77.2% AD, 74.7% CMC, 49.5% premature menopause, 29.7% autoimmune intestinal dysfunction, 27.8% autoimmune thyroid diseases, 25.9% autoimmune gastritis/pernicious anemia, 25.3% ectodermal dystrophy, 24% alopecia, 21.5% autoimmune hepatitis, 17% vitiligo, 13.3% cholelithiasis, 5.7% connective diseases, 4.4% asplenia, 2.5% celiac disease and 13.9% cancer. Overall, 991 diseases (6.3 diseases/patient) were found. Interferon-ω Abs (IFNωAbs) were positive in 91.1% of patients. Overall mortality was 14.6%. The AIRE mutation R139X was found in 21.3% of tested alleles, R257X in 11.8%, W78R in 11.4%, C322fsX372 in 8.8%, T16M in 6.2%, R203X in 4%, and A21V in 2.9%. Less frequent mutations were present in 12.9%, very rare in 9.6% while no mutations in 11% of the cases.

CONCLUSIONS

In Italy, APS-1 is a rare disorder presenting with the three major manifestations and associated with different AIRE gene mutations. IFNωAbs are markers of APS-1 and other organ-specific autoantibodies are markers of clinical, subclinical or potential autoimmune conditions.

A case report and literature review: Identification of a novel AIRE gene mutation associated with Autoimmune Polyendocrine Syndrome Type 1 in East Asians

RATIONALE

Autoimmune polyendocrine syndrome type 1 (APS-1), also referred as the autoimmune polyendocrinopathy candidiasis-ectodermal dystrophy (APECED), is a rare autosomal inherited disease predominantly among Caucasians from Northern Europe. This syndrome is very rare in East Asian population.

PATIENTS CONCERNS

Here, we describe a case of a 15-year-old Chinese boy admitted due to a 1-month history of intermittent fatigue, nausea, vomiting, and diarrhea. His symptom became worse accompanied with chest tightness 4 days before admission. On physical examination, his temperature was 38.5°C, blood pressure was 75/38 mm Hg, and pulse was 98/min. He was a thin boy with mild hyperpigmentation and xanthochromia.

DIAGNOSIS

After abdominal computed technology and laboratory tests, his diagnosis was APS-1 accompanied with adrenal crisis. Further investigation on whole-exome sequencing revealed a novel homozygous mutation c.47C>G (p.T16R) in exon 1 in the autoimmune regulator (AIRE) gene.

INTERVENTIONS

This patient underwent replacement therapy of glucocorticoids, corticosteroid, and levothyroxine, as well as calcium and calcitriol supplementation.

OUTCOMES

He continues to do well 4 years after his hospitalization. During his last follow-up, he had serum thyroid-stimulating hormone level of 3.07 μIU/mL, free triiodothyronine level of 1.92 pg/mL, and free thyroxine level of 13.95 pg/mL. His serum cortisol and ACTH (8 a.m.) levels were 28.53 μg/dL and 69.48 pg/mL, respectively.

LESSONS

APS-1 is very rare in East Asians and the variable clinical presentations of the disease make the initial diagnosis especially difficult. Autoimmune thyroiditis, type 1 diabetes mellitus, and hepatitis were the three most frequent minor components of APS-1 in East Asian patients with age of onset in late teens and 20s. Sequence analysis of AIRE gene is necessary to verify its diagnostic efficacy in association with clinical findings.

A novel compound heterozygous mutation of the AIRE gene in a patient with autoimmune polyendocrine syndrome type 1

Autoimmune polyendocrine syndrome type 1 (APS-1), or autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy is a rare, autosomal recessive autoimmune disease caused by a mutation of the autoimmune regulator (AIRE) gene. The main symptom triad in APS-1 comprises chronic mucocutaneous candidiasis, adrenal insufficiency, and hypoparathyroidism. Various autoimmune diseases and ectodermal abnormalities are also commonly associated with the syndrome. The treatment of APS-1 includes hormone replacement and symptom control. It is important to monitor such patients for clinical manifestations of their disease through regular follow-up. We report the case of a 10-year-old Korean girl with APS-1 due to a novel compound heterozygous mutation of the AIRE gene. This patient's main clinical manifestations were adrenal insufficiency and chronic mucocutaneous candidiasis. The patient had a previously known pathogenic variant of c.1513delG (p.Ala505ProfsTer16), and a newly discovered variant of c.1360dupC (p.His454ProfsTer50).

AIRE: a missing link to explain female susceptibility to autoimmune diseases

Women are more susceptible to autoimmune diseases than men. Autoimmunity results from tolerance breakdown toward self-components. Recently, three transcription modulators were identified in medullary thymic epithelial cells that orchestrate immune central tolerance processes: the autoimmune regulator (AIRE), FEZ family zinc finger 2 (FEZF2 or FEZ1), and PR domain zinc finger protein 1 (PRDM1). Interestingly, these three transcription modulators regulate nonredundant tissue-specific antigen subsets and thus cover broad antigen diversity. Recent data from different groups demonstrated that sex hormones (estrogen and testosterone) are involved in the regulation of thymic AIRE expression in humans and mice through direct transcriptional modulation and epigenetic changes. As a consequence, AIRE displays gender-biased thymic expression, with females showing a lower expression compared with males, a finding that could explain the female susceptibility to autoimmune diseases. So far, FEZF2 has not been related to an increased gender bias in autoimmune disease. PRDM1 expression has not been shown to display gender-differential thymic expression, but its expression level and its gene polymorphisms are associated with female-dependent autoimmune disease risk. Altogether, various studies have demonstrated that increased female susceptibility to autoimmune diseases is in part a consequence of hormone-driven reduced thymic AIRE expression.

Novel sequence variation of AIRE and detection of interferon-omega antibodies in early infancy

OBJECTIVE

Autoimmune polyendocrine syndrome type I (APS I) is a rare primary immunodeficiency disorder characterized by chronic mucocutaneous candidiasis, multi-organ autoimmunity and ectodermal dysplasia. Autoantibodies to parathyroid and adrenal glands and type I interferons (IFN) are hallmarks of APS I, which results from mutations in the autoimmune regulator (AIRE) gene. We wished to study clinical, immunological and genetic features of APS I in Hungarian patients, and to correlate anti-IFN-omega serum concentration with APS I and other multi-organ autoimmune diseases.

DESIGN

Detailed analysis of patients with APS I and multi-organ autoimmune diseases.

PATIENTS

Seven patients with APS I and 11 patients with multi-organ autoimmune diseases were studied.

MEASUREMENTS

Mutational analysis was performed by bidirectional sequencing of AIRE. Antibodies against IFN-omega and endocrine organ-specific autoantigens were studied with radioimmunoassay. RFLP was performed by digestion of DNA with Hin6I restriction enzyme.

RESULTS

AIRE sequence analysis revealed homozygous c.769C>T mutations in three patients and compound heterozygous sequence variants (c.769C>T/c.44_66dup26bp; c.769C>T/c.965_977del13bp; c.769C>T/c.1344delC) in four patients with APS I. All the six live patients tested had markedly elevated IFN-omega antibodies, which were not found in heterozygous siblings or parents. One of the identified patients was negative for antibodies against IFN-omega at 6 weeks of age, but became positive at 7 months. At age 1, he is still without symptoms of the disease. In contrast to patients with APS I, no AIRE mutation or elevation of IFN-omega antibodies were detected in patients with multi-organ autoimmune diseases.

CONCLUSION

This is the first overview of patients diagnosed with APS I in Hungary. A novel c.1344delC mutation in AIRE was detected. Anti-IFN-omega antibodies seem to appear very early in life and are helpful to differentiate APS I from other multi-organ autoimmune diseases.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) in the Irish population

OBJECTIVE

To determine the Irish prevalence of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), the AIRE mutations involved and clinical features of this population.

METHODS

All patients were identified through paediatricians and endocrinologists in Ireland. Patients were invited to attend a multidisciplinary clinic.

RESULTS

Thirty-one patients (2-56 years), 18 female, were identified from 19 families giving an Irish prevalence of 1:130,000. Twenty-six patients had hypoparathyroidism, 21 had adrenal insufficiency (AI) and 10 of 16 had ovarian failure. Three affected patients have died. Many with hypoparathyroidism were resistant to 1-alpha-vitamin D. Two needed daily PTH injections. Mineralocorticoid deficiency as the first manifestation of AI was common. Chronic intra-oral candidiasis affected 25 patients and three had leukoplakia. Two had keratoconjuntivitis. Of 22 with AIRE gene analysis, three different mutations were identified, one of which is novel.

CONCLUSION

APECED is rare in Ireland. We saw a significant amount of non-endocrine disease but no ectodermal dystrophy. AIRE gene analysis reassured many siblings and identified individuals with APECED prior to any symptoms.