NLRP3 and Schnitzler syndrome: The NLRP3 V198M variant (previously described as V200M) [10] is of particular interest because it has been reported in both individual patients and families with apparently classical CAPS [4,10,15]; in association with other autoinflammatory syndromes [16,17]; in patients with apparently acquired autoinflammatory disorders including the IgM paraprotein-related Schnitzler syndrome [18]; and in healthy Caucasian controls with an allele frequency of between 0.0038 [10] and 0.0074 [11].