Danon disease is typically lethal by the mid-twenties in male patients due to cardiomyopathy. This report aims to describe two unrelated male patients showing mild manifestations of the disease. A 39-year-old man presented with a 10-year history of elevated serum creatine kinase levels with slowly progressive muscle weakness. Muscle pathology showed autophagic vacuoles with sarcolemmal features. Genetic testing revealed a hemizygous mutation in exon 9b, an alternatively spliced exon, of lysosome-associated membrane protein-2 (LAMP-2) (c.1097_1098delAA). Cardiac testing showed asymptomatic mild left ventricular hypertrophy. He had borderline intelligence. Early stage of retinopathy was detected. Another male patient, currently 53-year-old, had asymptomatic supraventricular extrasystole and muscle weakness but no intellectual disability, harboring the same mutation. He also had retinopathy. The present patients commonly carry a mutation in exon 9b of LAMP-2, suggesting that mutations in the exon are associated with a mild form of Danon disease.

由于心肌病，达农病通常会在二十多岁的男性患者中致命。本报告旨在描述两名无血缘关系的男性患者，表现出轻微的疾病症状。一名 39 岁男性，有 10 年血清肌酸激酶水平升高史，并伴有缓慢进行性肌无力。肌肉病理学显示具有肌膜特征的自噬空泡。基因检测显示，溶酶体相关膜蛋白 2 ( LAMP-2 ) (c.1097_1098delAA) 的外显子 9b（可变剪接外显子）存在半合子突变。心脏检查显示无症状的轻度左心室肥厚。他的智力处于边缘水平。检测到早期视网膜病变。另一名男性患者现年 53 岁，有无症状室上性期前收缩和肌无力，但无智力障碍，携带相同的突变。他还患有视网膜病变。目前的患者通常携带LAMP-2外显子 9b 突变，表明该外显子突变与轻度 Danon 病有关。