Description of a case of late-onset cryopyrin-associated periodic syndrome due to low-level somatic NLRP3 mosaicism

Cryopyrin-associated periodic syndromes (CAPS) usually present in early childhood as an urticaria-like skin rash associated with an increased inflammatory response, with additional manifestations (i.e. arthropathy, AA amyloidosis or deafness) typically restricted to certain phenotypes. CAPS are caused by dominantly inherited or de novogain-of-functionNLRP3 mutations. The introduction of next-generation sequencing (NGS) into clinics has revealed the important role of somatic NLRP3 mosaicism in these syndromes by means of its detection in a high proportion of patients who were apparently mutation-negative by Sanger sequencing. Thus, NGS technologies are becoming essential for routinely identifying the genetic cause of the suspected autoinflammatory disease.