Autosomal dominant hyper IgE syndrome (AD-HIES) caused by STAT3 gene mutation is a rare primary immunodeficiency disease. To better understand the disease, we described the clinical characteristics of 20 AD-HIES patients in Chongqing, China and explored the effect of mutations in different domains of STAT3 gene on the function of STAT3 protein by western blot and confocal microscopy. The mean age at onset was 0.12 years. The mean age at diagnosis was 5.31 years. The most common presentation was eczema, pneumonia, skin abscesses and chronic mucocutaneous candidiasis. Seven patients suffered from BCG complications. R382W/Q were identified in 12 patients, V637M mutation in 3 patients. Three patients have died. The phosphorylated STAT3 was expressed more in wild-type(WT) and R382W mutant STAT3 in the cytoplasm of COS7 cells with epidermal growth factor(EGF) stimulation, less in the V637M mutation and T620S mutation. Dynamic observation showed that STAT3 cytoplasmic accumulation and nuclear translocation occurred rapidly after EGF stimulation in WT-STAT3-GFP, the time of accumulation and nuclear translocation was later and the expression was less in R382W-STAT3-GFP compared with WT-STAT3-GFP, followed by V637M and T620S mutation. These results suggested that our patients had earlier onset, diagnostic age and higher rate of BCG complications. However, our patients had higher incidence of mortality though the earlier diagnostic age. We did not find a significant genotype/phenotype correlation, but Src homology 2 domain mutations (V637M and T620S) had a greater effect on STAT3 phosphorylation and nuclear translocation than DNA-binding domain mutation (R382W) in vitro.This article is protected by copyright. All rights reserved.