肯尼迪病的临床分析及分子遗传学诊断

目的 本文通过5例经基因检测明确诊断的肯尼迪病（Kennedy＇s disease,KD）患者,探讨KD的临床表现和辅助检查特点及诊断.方法 收集5例疑似KD患者的详细病史、体格检查、血液生化、肌电图和肌肉病理等资料,用PCR扩增并测序方法测定雄性激素受体（AR）基因1号外显子CAG的重复序列拷贝数.结果 KD主要临床表现是四肢肌肉萎缩、无力和肢体震颤,舌肌萎缩和构音障碍；部分患者出现内分泌症状和肌酸激酶（CK）增高.肌电图可见广泛神经源性损害和感觉神经传导速度下降.肌肉病理为神经性损害.患者AR基因CAG重复序列的重复次数为48 ～ 58次.结论 KD有相对独特的临床、电生理及病理特征,确诊有赖于AR基因的（CAG）n拷贝数的检测.

The clinical and molecular genetic studies of Kennedy's disease

Objective To discuss the clinical features and diagnosis of Kennedy disease.Methods three patients were clinically diagnosed as having Kennedy disease on the basis of their clinical features including slowing progression of disease,symptoms,nervous system signs,electromyography and nerve conduction velocity results and family history.Their CAG number from the repetitive CAG sequence in the first exon of androgen receptor gene was determined suing PCR.Results Patients were mainly presented with the lower motor neuron damage in the proximal limb and bulbar,including muscle atrophy,weakness and tremors of limbs.Additional symptoms were tongue muscle atrophy and dysarthria.Some patients had increased endocrine symptoms and significantly high levels of serum creatine kinase.EMG detected a widespread neuronal damage and decreased amplitude of SCV in all cases.There was a loss of myelinated fiber in nerve biosy.The CAG repeat number in AR gene was from 48 to 58,respectively.Conclusions There are relatively unique clinical,neuropathysiological and neuropathological characteristics of KD,and its definite diagnosis should be made by genetic analysis.