Diagnosis of cryopyrin-associated periodic syndrome: challenges, recommendations and emerging concepts.

Cryopyrin-associated periodic syndrome are rare autosomal dominantly inherited diseases. They include three overlapping phenotypes: familial cold autoinflammatory syndrome, Muckle-Wells syndrome, and chronic infantile neurological cutaneous articular syndrome/neonatal onset multisystem autoinflammatory syndrome (NOMID/CINCA). Recurrent fevers, joint pain, and urticarial skin rash are the main clinical features of these conditions. Renal amyloidosis and sensorineural complications may occur. Gain-of-function mutations in NLRP3 gene are responsible for the overactivation of the NLRP3 inflammasome, a multimolecular complex involved in the inflammatory process. Missense mutations are almost always encountered, particularly in exon 3, which encodes the nucleotide-binding domain. Mosaicism is not rare, especially in CINCA/NOMID. Next-generation sequencing will grant access to new insights about NLRP3 implication in oligogenic and multifactorial diseases.