Abstracts： Objectives To investigate the clinical features and LAMP2 gene mutation a case with hypertrophic cardiomyopathy due to Danon disease. Methods A boy (proband) of hypertrophic cardiomyopathy due to Danon disease was hospitalized in the Department of Pediatrics of Peking University First Hospital on October, 2013. He was the first child of non-consanguineous Chinese couples. Gene analysis was performed by direct sequencing. Results The patient had not any symptoms with normal intelligence and physical development. Elevated serum alanine aminotransferase had been noticed in a medical examination for entry to kindergarten. His serum alanine aminotransferase, glutamic-oxaloacetic transaminase, creatine phosphokinase, creatine kinase-MB, lactate dehydrogenase, and hydroxybutyrate dehydrogenase were elevated. Electrocardiograph showed left ventricular high voltage, prolonged Q-T interval. Ultrasonic cardiogram showed ventricular septum and left ventricular wall thickening, left ventricular enlargement, increased trabecular of left ventricular apex, and mitral inadequacy, supporting the diagnosis of hypertrophic cardiomyopathy. A homozygous mutation, c.973-974insC (p.L325fs) was detected on LAMP2 gene of the patient. His mother had unexplained hypertrophic cardiomyopathy. She carries a heterozygous mutation c.973-974insC. His father is healthy without any mutation on LAMP2. c.973-974insC was a novel mutation, leading to frameshift mutation and a premature termination codon. Conclusions Danon disease is a rare fatal genetic cardiomyopathy without effective treatment. In this study, a Chinese boy and his mother with Danon disease were firstly diagnosed by gene analysis. LAMP2 gene study is important for the diagnosis of Danon disease and genetic counseling of the family.
