Screening of pathogenic genes in Chinese patients with arrhythmogenic right ventricular cardiomyopathy

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable cardiac disease predominantly caused by mutations in desmosomal protein genes. Previous genetic analyses of the Chinese ARVC population are limited to small size and restriction to a single gene. This study was aimed to investigate the genotype in a large series of Chinese patients with ARVC through comprehensively screening nine ARVC-causing genes. METHODS: A total of 100 unrelated ARVC patients and 300 age, gender and ethnicity matched healthy controls were genetically tested with multiplexing targeted resequencing for nine previously reported ARVC-causing genes, including plakophilin-2, desmoplakin, desmoglein-2, desmocollin-2, plakoglobin, transforming growth factor beta-3, transmembrane protein 43, desmin and Lamin A/C. RESULTS: Fifty-nine mutations were identified in 64% of the patients, among which, 93% were located in desmosomal protein genes. Plakophilin-2 mutations accounted for 54% of the total and 58% of the desmosomal mutations, with a truncating mutation type making up about 2/3 of the plakophilin-2 mutations. Only four mutations were found in non-desmosomal genes; two in transmembrane protein 43 and two in transforming growth factor beta-3. Two of them (one of each gene) appeared as single missense mutations. No mutation was identified in desmin or Lamin A/C. Multiple mutations were found in 23% of the patients, with plakophilin-2 being found in 57% of the multi-mutation carriers. CONCLUSIONS: Plakophilin-2 was the most common gene mutation that was identified in Chinese ARVC patients. Non-desmosomal genes should be added to desmosomal protein genes when performing molecular genetic screening in patients with suspected ARVC.