基因确诊的肯尼迪病1家系报告

A report of a family of Kennedy's disease with genetic diagnosis

目的研究肯尼迪病(KD)的遗传学和临床特点,并讨论基因检测对该病确诊及预防的意义。方法对1名疑诊为KD的患者的临床资料进行收集和分析,完善血常规、电解质、肝功能、肌酶谱、性激素、肌电图等检查。收集患者及3位亲属的外周血,检测雄激素受体(AR)基因第一外显子中CAG的重复次数。结果患者有躯干、四肢及延髓肌肉的无力、萎缩、震颤,伴有乳腺发育;血清肌酸激酶升高;血清孕酮水平升高,睾酮及其他指标正常;肌电图示神经源性损害。先证者CAG重复数为48次,其二哥为49次,先证者的女儿为48/22次,为携带者。先证者的儿子无该突变。结论 KD是一种X-连锁隐性遗传病,主要临床特点为缓慢进展的脊髓、延髓肌肉的萎缩和无力。基因检测不但能帮助患者及其家庭确诊、筛查及预防该病,而且为遗传病的探索提供了支持。

Objective To investigate the genetic and clinical features of Kennedy’s disease （KD） and discuss the significance of gene detection in the diagnosis and prevention of the disease. Methods The clinical data of 1 a patient with suspected KD were collected and analyzed,and examinations of blood routine,electrolytes,liver function,muscle enzymes,sex hormones as well as EMG were completed. The peripheral blood of the patient and 3 relatives was collected to detect the numbers of CAG repeats in exon 1 of the androgen receptor（AR） gene. Results The patient had weakness,atrophy and tremor of trunk muscles,limb muscles and bulbar muscles,accompanied by gynecomastia. The level of serum creatine kinase increased. Serum progesterone level increased while levels of testosterone and other sex hormones were in normal range. EMG showed neurogenic damage. The numbers of CAG repeats were found to be 48 in the proband,49 in his second elder brother,48 and 22 in the proband’s daughter who was a carrier. The proband’s son didn’t have the mutation. Conclusion KD is an X-linked recessive genetic disease,whose main clinical features are slowly progressing atrophy and weakness of the spinal and bulbar muscles. Gene detection can not only assist patients and their families to diagnose,screen and prevent the disease,but also provide support for the exploration of hereditary diseases.