[Immune dysregulation syndrome caused by STAT3 gene mutation: a complicated case study].

A boy, aged 4 years and 6 months, had disease onset of fever, cough, pale complexion, and weakness, with hepatosplenomegaly, lymphadenectasis, and pancytopenia. He had been having repeated respiratory and digestive tract infections. Gene detection showed a pathogenic heterozygous mutation, c.C2147 > T(p.T716M), in the STAT3 gene. The boy was thus diagnosed with immune dysregulation syndrome. Anti-infective therapy and irregular corticosteroid therapy had an unsatisfactory effect in the early stage, but the symptoms improved after regular corticosteroid therapy. This article reported the case of immune dysregulation syndrome caused by STAT3 gene mutation and summarized the epidemiology, clinical features, diagnosis, and treatment of this disease, which can provide a reference for early diagnosis, treatment, and future studies of this disease.