p.Arg636Cys: A Pathogenic Variant Identified in a Family with Several Cases of Unexpected Sudden Deaths.

: Dilated cardiomyopathy (DCM) can be an inherited condition related to premature sudden cardiac death (SCD). Pathogenic variants in some genes, like , , or , have been linked to an increased risk of SCD. Although genetic study can help to stratify the arrhythmic risk, there are no specific guidelines for carriers' management. We aimed to evaluate the genetic profile and clinical features of all DCM patients with pathogenic variants in : We identified all carriers of pathogenic variants in in a single national center that specializes in inherited cardiac conditions. Forensic and molecular autopsies provided crucial information. : We identified a large family with inherited DCM due to p.Arg636Cy and several SCDs. The proband was a 37-year-old male who suffered an unexpected SCD despite presenting a mild DCM phenotype with normal left ventricular ejection fraction. Family screening identified four other carriers, who were asymptomatic, but presented concealed mild DCM phenotypes. Family history revealed that six other relatives (two of them obligate carriers) had also suffered sudden deaths at young ages. : We present an informative family with DCM, due to p.Arg636Cys, and high rates of SCD, even in members with mild DCM phenotypes. ICD implantation to prevent SCD should be carefully evaluated in all p.Arg636Cys carriers. Moreover, the frequent development of AF and HF progression requires specific awareness.