MANAGEMENT OF ENDOCRINE DISEASE: Carney complex: clinical and genetic update 20 years after the identification of the CNC1 (PRKAR1A) gene

Described for the first time in 1985, Carney complex (CNC) is a rare dominantly inherited multiple neoplasia syndrome with almost full penetrance and characterized by both endocrine – primary pigmented nodular adrenocortical disease with Cushing’s syndrome, acromegaly and thyroid tumors – and non-endocrine manifestations such as cardiac, cutaneous and mucosal myxomas, pigmented cutaneous lesions, psammomatous melanotic schwannoma, osteochondromyxoma and a wide range of other tumours with potential malignancy. The pathophysiology of CNC is a model of dysregulation of the cAMP/PKA signalling in human diseases. As described 20 years ago, inactivating heterozygous mutations of PRKAR1A formerly known as CNC1, encoding the regulatory subunit 1α of protein kinase A, are identified in more than 70% of the index cases, while inactivating mutations of genes encoding phosphodiesterases are found in rare and particular forms of the complex. There is at present no medical specific treatment for CNC, every confirmed or suspected CNC patient should be managed by a multi-disciplinary team according to each manifestation of the disease and offered a long-term follow-up and genetic counselling. The better knowledge that we have now of this fascinating rare disease and its genetics will help to improve patients outcome.