患者45岁,男性。自幼发育延迟,智力低下,有白发,说话声音高调。44岁时做过白内障手术。从20个月前开始出现数分钟的意识丧失发作,发作时的心电图呈现完全性房室传导阻滞,收入本院。父母系表兄妹结婚。弟兄8人中2人有与患者同样的查体所见。颜貌呈老人样,生殖器官发育不全,智力低下,全部肌肉有萎缩倾向,但无肌力低下及肌强直。虽然入院时心电图呈现窦性心律,电轴左偏,右束支传导阻 45 years old, male. Delayed childhood development, mental retardation, gray hair, high-profile voice. 44 years old had cataract surgery. From 20 months ago began to appear episodes of loss of consciousness, the onset of ECG showed a complete atrioventricular block, income in this hospital. Parents cousins ​​get married. Two of the eight brothers have the same physical findings as the patients. The appearance of elderly like, genital hypoplasia, mental retardation, all muscles have a tendency to shrink, but no muscle weakness and muscle rigidity. Although the electrocardiogram showed sinus rhythm at admission, left axis deviation, right bundle branch resistance