Abstract: Somatic mutations are de novo mutations occur after zygogenesis, which are distinguished from germline mutations by nonhereditary acquisition. Somatic mutations are caused by multiple internal and external stimuli, and are influenced by microenvironment, gene functions, and developmental timing, hence the characteristics of various and random. Whereas the role of somatic mutations in malignant proliferative diseases is longrecognized, growing evidence of somatic variants in immune cells in nonmalignant immunerelated disorders has been no focus since recent years. We reviewed the molecular mechanisms underlying somatic mutations and its recent progress in autoinflammatory and autoimmune diseases, for the purpose of emphasizing the significance of somatic mutations in the diagnosis and treatment of diseases related to dysregulated gene functions.

Key words: somatic mutations, mosaic, autoinflammatory disease, autoimmune disease, mechanism