First Description of Late-Onset Autoinflammatory Disease Due to Somatic NLRC4 Mosaicism.

We have identified the post-zygotic p.Ser171Phe NLRC4 variant as a plausible cause of the disease in the enrolled patient. Functional and structural studies clearly support for the first time its gain-of-function behavior consistent with previously reported NLRC4 pathogenic variants. These novel evidences should be considered in the diagnostic workup of patients with uncharacterized AID starting during adulthood.