Dilated cardiomyopathy (DCM) is a disease of the heart muscle characterized by ventricular dilation and a left ventricular ejection fraction of less than 40%. Unlike hypertrophic cardiomyopathy (HCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC), DCM-causing mutations are present in a large number of genes. In the present study, we report a case of the early age of onset of DCM associated with a pathogenic variant in the RBM20 gene in a patient from India. A 19-year-old Indian male diagnosed with DCM was suggested for heart transplantation. His ECG showed LBBB and echocardiography showed an ejection fraction of 14%. He had a sudden cardiac death. A detailed family history revealed it to be a case of familial DCM. Genetic screening identified the c.1900C>T variant in the RBM20 gene which led to a missense variant of amino acid 634 (p.Arg634Trp). To the best of our knowledge, the variant p.Arg634Trp has been earlier reported in the Western population, but this is the first case of p.Arg634Trp in an Indian patient. The variant has been reported to be pathogenic at an early age of onset; therefore, close clinical follow-up should be done for the family members caring for the variant.

中文翻译：

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一名印度患者家族性扩张性心肌病，RBM20突变：一例病例报告

扩张型心肌病（DCM）是一种以心室扩张为特征且左心室射血分数小于40％的心肌疾病。与肥厚型心肌病（HCM）和致心律失常性右室心肌病（ARVC）不同，引起DCM的突变存在于许多基因中。在本研究中，我们报道了印度患者RBM20基因致病变异相关的DCM发病年龄偏早的情况。建议将一名19岁的印度男性诊断为DCM进行心脏移植。他的心电图显示LBBB，超声心动图显示射血分数为14％。他死于心脏猝死。详细的家族史显示这是家族性DCM的案例。遗传筛选鉴定出c.1900C> RBM20基因中的T变体导致氨基酸634（p.Arg634Trp）的错义变体。据我们所知，西方人群中较早报道了p.Arg634Trp变异体，但这是印度患者中的第一例p.Arg634Trp病例。据报道，该变体在发病初期是致病的。因此，应该为照顾该变体的家庭成员进行密切的临床随访。