Description

Polyendocrine syndromes are defined by the presence of multiple autoimmune disorders. Three distinct forms have been described; autoimmune polyglandular syndrome (APS) type 1 , APS type 2 and APS type 3. Autoimmune polyglandular syndrome type 1 is caused by a mutation in a gene called either AIRE (autoimmune regulator) or APECED (autoimmune polyendocrinopathy-candidiasisectodermal dystrophy) which encodes a DNA transcription factor. The main clinical features of APS type 1 are mucocutaneous candidiasis, autoimmune mediated endocrine organ damage and ectodermal dystrophy.
Addisons disease and hypoparathyroidism are the major endocrine diseases associated with this condition. Premature ovarian failure, autoimmune hepatitis, and autoimmune skin disease are also common complications. The onset of APS type 1 typically occurs in childhood and multiple disease complications evolve, as the patient gets older. Autoimmune polyglandular syndrome type 2 consists of autoimmune Addisons disease, autoimmune thyroid disease and type 1 diabetes mellitus. In contrast with APS type 1, disease onset occurs in adult life, there is a female predominance, polygenic inheritance and linkage to the MHC Class II alleles DR3 and DR4. APS type 3 consists of autoimmune thyroid disease and at least one other autoimmune disorder except Addisons disease.