7例Danon病患者临床和肌肉病理特点分析

Clinical and pathological features of Danon disease： a study of seven patients

目的 总结Danon病患者的临床表现、实验检查结果和骨骼肌的组织病理学特点.方法 对7例Danon病患者的临床及实验室检查结果进行总结分析.结果 1例未行基因检测,余6例患者溶酶体膜相关蛋白2（lysosomal-associated membrane protein 2）基因均为移码突变.7例患者均为男性,就诊年龄为13～20岁,平均16岁.临床以心脏受累为主,肌力可正常或轻度无力,智力受损常见,2例患者有斜视.患者肌酸激酶升高明显（7/7）,超声心动检查提示左室肥厚（5/7）、左室扩张（1/7）、左室肥厚合并左室扩张（1/7）.心电图检查提示预激综合征（5/7）.肌电图未见异常（2/2）.对7例患者均行肌肉活组织检查,可见肌纤维内出现自噬性空泡,dystrophy和spectfin等免疫组织化学染色可见膜阳性空泡和颗粒.3例患者心肌活组织检查可见部分空泡化肌纤维.结论 Danon病多表现为青少年男性起病的肥厚性心肌病,伴肌酸激酶升高,骨骼肌无力和智力低下不突出,往往被忽视而误诊为单纯性肥厚性心肌病.心力衰竭是影响预后的因素.肌肉病理改变与心肌类似,以出现多发膜性自噬空泡为特征,对疾病诊断有较高的提示意义.

Objective To summarize the clinical,laboratory and the muscle histopathology features of patients with Danon disease.Method The clinical documents and laboratory data of 7 patients with Danon disease were analyzed retrospectively.Results Genetic testing was performed in 6 patients and lysosomal-associated membrane protein 2 frame-shift mutations were found.Patients were all male and the age at diagnosis ranged from 13 to 20 years with an average of 16 years.Among the 7 patients,cardiomyopathy was the main clinical manifestation,myopathy was mild or subclinical and mental retardation was common.Besides,2 patients had strabismus.Serum creatine kinase was elevated in all the patients.Echocardiography revealed hypertrophic cardiomyopathy in 5 patients,dilated cardiomyopathy in 1 patient and hypertrophic cardiomyopathy combined with dilated cardiomyopathy in 1 patient.Electrocardiogram revealed pre-excitation syndrome in 5 patients.Electromyogram showed neither myogenic nor neurogenic changes in 2 patients.Autophagic vacuoles in muscle fibers were the character of muscle pathology,and some cytoplasmic vacuoles and granules were positive in dystrophin and spectrin immumohistochemical staining.Endomyocardial biopsy of 3 patients showed extensive vacuoles within some cardiac muscle fibres.Conclusions Danon disease often affects male adolescents,presenting with hypertrophic cardiomyopathy and elevated serum creatine kinase concentration,and myopathy and mental retardation are often mild and can be clinically silent sometimes,which are usually neglected and misdiagnosed as hypertrophic cardiomyopathy.What is more,heart failure is an important predictor of prognosis.Both skeletal and cardiac muscle pathology is characterized by cytoplasmic autophagic vacuoles,even when weakness is not obvious in skeletal muscles.Therefore,skeletal muscle pathology is very important to diagnosis of the disease.