Cardiovascular Involvement in SYNE Variants: A Case Series and Narrative Review

Cardiac laminopathies encompass a wide range of diseases caused by defects in nuclear envelope proteins, including cardiomyopathy, atrial and ventricular arrhythmias and conduction system abnormalities. Two genes, namely LMNA and EMD, are typically associated with these disorders and are part of the routine genetic panel performed in affected patients. Yet, there are other markedly fewer known proteins, the nesprins, encoded by SYNE genes, that play a pivotal role in connecting the nuclear envelope to cytoskeletal elements. So far, SYNE gene variants have been described in association with neurodegenerative diseases; their potential association with cardiac disorders, albeit anecdotally reported, is still largely unexplored. This review focuses on the role of nesprins in cardiomyocytes and explores the potential clinical implications of SYNE variants by presenting five unrelated patients with distinct cardiac manifestations and reviewing the literature. Emerging research suggests that SYNE-related cardiomyopathies involve disrupted nuclear–cytoskeletal coupling, leading to impaired cardiac function. Understanding these mechanisms is critical for furthering insights into the broader implications of nuclear envelope proteins in cardiac health and for potentially developing targeted therapeutic strategies. Additionally, our data support the inclusion of SYNE genes in the cardiac genetic panel for cardiomyopathies and cardiac conduction disorders.