Abstract: To explore the specific clinical phenotype of Wiskott-Aldrich syndrome（WAS）. The clinical data and laboratory results of one WAS patient characterized by monocytosis were retrospectively analyzed，and the relevant literature was reviewed. A boy aged 3 months visited us for thrombocytopenia and anemia. in March，2017 He also presented with hepato splenomegaly and intermittent bloody stools. The routine blood test showed an increased number of leukocytes，neutrophils，and monocytes，decreased number of hemoglobin and platelet volume.The primitive naive cells in peripheral blood and bone marrow were not high.So a diagnosis of JMML was initially suspected.However，no abnormalities were found in JMML-related genes or chromosome karyotypes. Low WAS protein（WASP）expression level was determined by flow cytometry.Genomic sequencing showed a hemizygous variation of c.151G>T（p.V51F）of WAS gene.Finally，the patient was diagnosed with WAS. WAS shows significant clinical phenotypic variations.Screening for WASP and WAS gene is recommended for boys with early onset thrombocytopenia.

Key words: Wiskott-Aldrich syndrome, juvenile myelomonocytic leukemia, clinical phenotype

摘要： 为了探讨湿疹-血小板减少伴免疫缺陷综合征（WAS）的特殊表型。回顾性分析2017年3月重庆医科大学附属儿童医院风湿免疫科收治的1例以单核细胞增多为特征的WAS病例的临床资料及实验室检查结果，并复习相关文献。结果发现，患儿出生后以血小板减少及贫血为主要表现，伴肝脾肿大及间断血便，血常规提示白细胞、中性粒细胞及单核细胞增高，血红蛋白及血小板降低，外周血及骨髓原始幼稚细胞不高，考虑幼年型粒单核细胞白血病（JMML）可能。JMML相关基因和染色体核型未见异常。由于WAS蛋白（WASP）明显表达减少，WAS基因存在一处半合子突变（c.151G>T，p.V51F），最终确诊为WAS。WAS临床表型变异大。对于早发血小板减少的男婴，建议检测WAS蛋白和WAS基因进行筛查。

关键词: 湿疹-血小板减少伴免疫缺陷综合征, 幼年型粒单核细胞白血病, 临床表型