Rare variants in the FBN1 gene are associated with sporadic dilated cardiomyopathy in a Chinese Han population

Introduction: Dilated cardiomyopathy (DCM) represents a diverse set of myocardial diseases characterized by notable genetic heterogeneity. Although over 50 genes have been associated with DCM, these collectively explain 35% of idiopathic DCM cases. Variants in the FBN1 gene encoding fibrillin-1 are primarily linked to connective tissue disorders. Considering the potential of these disorders to impact myocardial tissue, this study probes into the possible association between FBN1 variants and DCM. Aim: The objective of this study was to investigate the association between FBN1 variants and DCM in a Chinese Han population. Methods and Results: We performed whole-exome sequencing (WES) to identify rare FBN1 variants among 1,059 DCM cases and 514 controls. Utilizing a case-control strategy and the optimal sequence kernel association test (SKAT-O), we found a significant enrichment of rare deleterious FBN1 variants in DCM patients (19 of 1,059 vs. 0 of 514, PSKAT-O = 7.49E-04). Clinical characteristics analysis indicated a higher occurrence of atrial fibrillation and a higher rate of implantable cardioverter-defibrillator (ICD) implantation among DCM patients carrying FBN1 variants (FBN1+) compared to non-carriers (FBN1-). However, these FBN1 variants did not significantly affect primary endpoints, defined as cardiac mortality or heart transplantation, yet appeared to increase the risk of secondary endpoints, including all-cause mortality or heart failure recurrence. Conclusion: The findings suggest an association between rare deleterious variants in the FBN1 gene and DCM in a Chinese Han population. Our findings underline the importance of further research to validate these results and elucidate the role of FBN1 in DCM. Potential Impact of the findings: This research provides fresh insights into the potential role of FBN1 rare variants in DCM, pointing to new directions for future genetic studies and potential therapeutic strategies in DCM management.