text: 表现为外周血B细胞极少或缺如淋巴细胞，B细胞数少于5个），浆细胞亦缺乏淋巴器官生发中心缺如血IgM、IgG和IgA均明显下降或缺如IgG＜2g/L，IgA＜0.1g/L）；T细胞数量和功能正常Btk蛋白表达功能也各异，临床表现轻重不一，因此凡男孩低Ig血症者，均应进行Btk基因筛查。
entities.entity: 血B细胞
entities.label: bod
entities.entity: 外周血B细胞极少或缺如
entities.label: sym
entities.entity: 淋巴细胞
entities.label: bod
entities.entity: B细胞
entities.label: bod
entities.entity: 浆细胞
entities.label: bod
entities.entity: 浆细胞亦缺乏
entities.label: sym
entities.entity: 淋巴器官
entities.label: bod
entities.entity: 淋巴器官生发中心缺如
entities.label: sym
entities.entity: 血IgM
entities.label: bod
entities.entity: IgG
entities.label: bod
entities.entity: IgA
entities.label: bod
entities.entity: 血IgM、IgG和IgA均明显下降或缺如
entities.label: sym
entities.entity: IgG
entities.label: bod
entities.entity: IgA
entities.label: bod
entities.entity: T细胞
entities.label: bod
entities.entity: T细胞数量和功能正常
entities.label: sym
entities.entity: Btk蛋白
entities.label: bod
entities.entity: 低Ig血症
entities.label: dis
entities.entity: Btk基因筛查
entities.label: pro