The distribution of different CAPS phenotypes varies around the world; up to 75% of CAPS patients in North America are diagnosed as FCAS, due to a founder mutation (p.Leu353Pro) in NLRP3 gene, MWS represents the most common phenotype reported in Europe, while CINCA/NOMID patients are less common since the majority of cases are caused by de novo NLRP3 mutations (12) (Table 2). The gene discussed is NLRP3; the disease is cryopyrin-associated periodic syndrome.