Autoimmune polyendocrine syndrome type 1
Autoimmune polyendocrine syndrome type 1, is a subtype of autoimmune polyendocrine syndrome. It causes the dysfunction of multiple endocrine glands due to autoimmunity. It is a genetic disorder, inherited in autosomal recessive fashion due to a defect in the AIRE gene (autoimmune regulator), which is located on chromosome 21 and normally confers immune tolerance.
Signs and symptoms
APS-1 tends to cause severe symptoms. These are present from early in life, usually around 3.5 years of age. Common symptoms of APS-1 include:- Chronic mucocutaneous candidiasis.
- Hypoparathyroidism.
- Addison's disease.
- Ectodermal dystrophy.
- Autoimmune hepatitis.
- Hypogonadism.
- Vitiligo.
- Alopecia.
- Malabsorption.
- Pernicious anemia.
- Cataract.
- Cerebellar ataxia.
Cause
APS-1 is caused by a mutation in the AIRE gene, encoding a protein called autoimmune regulator. This is found on the 21q22.3 chromosome location, hence chromosome 21. The AIRE gene may be affected by any of at least 186 mutations. APS-1 may be inherited in an autosomal recessive manner.Different mutations are more common in different geographic regions. R139X is a common mutation in Sardinia. R257* is a common mutation in Finland. Both of these mutations are nonsense mutations: the asterisk and the "X" both indicate a stop codon. A 13-base-pair deletion in the AIRE gene, c.967-979del13bp, has been identified in APS-1 patients in Norway, Britain and North America.