运动失调性毛细血管扩张症(AT)是一种以小脑共济失调、免疫功能缺陷和对DNA 放射性损伤修补能力丧失为标志的多系统疾病。已知免疫功能的缺陷包括B 细胞抗体产生转换能力的丧失和T 细胞功能及数量的改变。其中B 细胞抗体产生转换能力的丧失表现为IgM 含量的正常或升高及IgG_2、IgG_4、IgA 和IgE 的选择性缺乏,而对T 细胞功能和数量的改变则了解不足。本文作者通过对AT 患者两类T 细胞抗原受体(一类是由 Motor dysatomic telangiectasia (AT) is a multisystem disorder characterized by cerebellar ataxia, impaired immune function, and loss of ability to repair DNA radioactive lesions. Known defects in immune function include loss of B-cell antibody-producing ability to convert and changes in T cell function and amount. Among them, the loss of B-cell antibody production and conversion ability is the normal or elevated IgM level and the selective deficiency of IgG 2, IgG 4, IgA and IgE, while the change of T cell function and quantity is poorly understood. The authors pass on two types of T-cell antigen receptors in AT patients (one is by