Genetic characterization of dilated cardiomyopathy patients undergoing heart transplantation in the Chinese population by whole-exome sequencing.

Background: Dilated cardiomyopathy (DCM) is one of the most frequent causes of heart failure and heart transplantation (HTx). The genetic basis of DCM among patients undergoing HTx remains to be further studied. This study aimed to characterize the genetic basis of DCM HTx in the Chinese population.

Methods: In total, 208 unrelated DCM patients who underwent HTx at Fuwai Hospital between June 2004 and June 2017 were included in this study. Whole-exome sequencing (WES) was performed for all patients. Gene burden analysis, variant classification, and genotype-phenotype correlation analysis were subsequently performed.

Results: After completing the bioinformatics analysis, gene burden analysis suggested that titin (TTN), filamin C (FLNC) and lamin A/C (LMNA) were significantly enriched with rare protein-altering variants. The frequencies of TTN and FLNC truncating variants in our cohort were 18.8% and 8.7%, respectively. Among the 165 rare variants in high evidence DCM-related genes, 27 (16.4%) and 59 (35.8%) were interpreted as pathogenic (P) and likely pathogenic (LP), respectively. In addition, 41 (47.7%) and 16 (18.6%) of these 86 P/LP variants are located in TTN and FLNC, respectively. The FLNC group contained more patients with NYHA class IV than the P/LP-negative group (FLNC, 16/18 vs. P/LP-negative, 81/123, P = 0.049).

Conclusions: Based on WES, we provided a primary genetic spectrum of DCM patients undergoing HTx in the Chinese population. TTN and FLNC harbour the most P/LP variants. FLNC truncation may lead to severe clinical symptoms in DCM patients.