A 2-year-old Japanese girl with TNF receptor-associated periodic syndrome: A case report of the youngest diagnosed proband in Japan.

We report a 2-year-old girl with tumor necrosis factor receptor-associated periodic syndrome (TRAPS) who is the youngest proband diagnosed in Japan. Recurrent fever had started at her 6 months of age, and she had the familial history of recurrent fever, suggesting underlying genetic disorder, in her father and grandfather. Careful clinical observation of characteristics of fever with disease course and the familial history of recurrent fever may lead to diagnosis of TRAPS in early infancy.