湿疹、血小板减少伴免疫缺陷综合征1例临床表型及基因突变分析

目的:对1例四川籍湿疹、血小板减少伴免疫缺陷综合征儿童(Wiskott-Aldrich syndrome,WAS)临床表现及分子遗传学特征进行分析,为其家系成员提供病因诊断和遗传咨询。方法:收集在我院诊治的1例WAS患儿的临床病例资料,抽取患儿外周静脉血,常规提取基因组DNA,采用聚合酶链反应(PCR)扩增WASP基因,对扩增产物进行测序和序列分析,寻找基因突变位点,进行基因诊断。结果:(1)患儿系1岁4月男性,生后1月即出现血小板减少,伴有湿疹、反复上呼吸道感染史,此次因发热、间断血便入院,血清IgA升高,给予丙种球蛋白及激素治疗效果不佳,临床评分为3分;(2)WASP基因Exon1存在无意义突变c.100CT(p.Arg 34x),编码蛋白质提前终止于氨基酸第34位,导致蛋白缺失;WASP基因Exon11上存在错义突变c.1378CT(P.Pro460Ser)。结论:根据患儿临床表现、实验室检查及分子遗传学检测结果,可临床诊断为WAS患者。

Clinical and genetic analysis in a Chinese boy with eczema,thrombocytopenia associated with immunodeficiency syndrome

Objective： To explore the clinical and genetic characteristics of a patient with eczema, thrombocytopenia associated with immunodeficiency syndrome（Wiskott-Aldrich sydrome, WAS） from Sichuan province. Methods： The clinical data of a case of WAS in West China Second University Hospital was retrospectively analyzed. With genomic DNA of patient extracted, WAS protein （WASP） gene was amplified with PCR and analyzed by direct sequencing. Results： （1） The patient was a 16 months boy. Thrombo- cytopenia appeared one month after his birth with repeated upper respiratory infections and eczema. He was admitted to hospital due to fever and intermittent hemafecia this time. Treatment with IVIG and glucocorticoid achieved poor effect. His clinical score was 3. （2） DNA sequencing revealed a nonsense mutation of Exonl in WASP gene c. 100C〉T（p. Arg 34x）, which leaded to protein deficiency, and a missense mutation in Exonll of WASP gene c. 1378C〉T（P. Pro460Ser）. Conclusion： Based on clinical manifestations, laboratory data and molecular genetic testing results of the child, the diagnosis of WAS was confirmed clinically.