Correlation of Ventricular Arrhythmias With Genotype in Arrhythmogenic Right Ventricular Cardiomyopathy

Abstract

A total of 90 unrelated Chinese subjects with definite (n=69), borderline (n=15), or possible (n=6) diagnosis of ARVC and 300 age-, sex-, and ethnicity-matched healthy control subjects were recruited for gene analysis at our center. ARVC was diagnosed in all patients according to the revised diagnostic Task Force Criteria. 17 None of the control subjects had a history of cardiovascular or other systemic diseases.This study was performed in accordance with the principles of the Declaration of Helsinki and approved by the Ethics Committees of our hospital. The informed consent for the electrophysiological (EP) study and genetic testing was provided by all participants. EP study was not performed on the control subjects. Clinical EvaluationClinical evaluation including 12-lead ECG and transthoracic echocardiography was performed in all cases. Cardiovascular magnetic resonance and 24-hour Holter monitoring were performed. The EP characteristics of ARVC were assessed by EP study, and the results were correlated with genetic testing of 9 genes that have previously been reported to be related to ARVC, including plakophilin-2 (PKP2), desmocollin-2 (DSC2), desmoglein-2 (DSG2), desmoplakin (DSP), plakoglobin (JUP), transforming growth factor-β3 (TGFβ3), transmembrane protein 43 (TMEM43), desmin (DES), and Lamin A/C (LMNA).All clinical data were reviewed independently by 3 cardiologists with resolution of differences by consensus.Background-Although mutations of several genes are associated with arrhythmogenic right ventricular cardiomyopathy (ARVC), the exact correlation between genotype and ventricular arrhythmia features remains unclear. This study was aimed to examine the possible association of the 9 known genes of ARVC with clinical and electrophysiological characteristics. Methods and Results-Ninety subjects diagnosed with ARVC who underwent electrophysiological study were recruited for screening the 9 known ARVC-causing genes. A total of 53 mutations were identified in 57 (63%) subjects. Mutation carriers had more frequent clinical ventricular tachycardia (VT; 89% versus 55%; P<0.001) and negative T waves in V 1 to V 3 (61% versus 33%; P=0.016). Subjects with plakophilin-2 (PKP2) mutations also had more frequent VT than those without mutations in PKP2. Comparison between subjects with multiple and single mutations showed that syncope occurred more often in the former group (58% versus 24%; P=0.018). VT was significantly more often induced in mutation carriers compared with noncarriers (75% versus 39%; P=0.001), as well as in PKP2 mutation carriers compared with subjects without PKP2 mutations (80% versus 48%; P=0.002). Induced VT with a rate ≥200 bpm was more often documented in mutation carriers (88% versus 54%; P=0.013), as well as in PKP2 mutation carriers (91% versus 67%; P=0.041). Conclusions-Pathogenic

Whole Genome Sequence Identified a Rare Homozygous Pathogenic Mutation of the DSG2 Gene in a Familial Arrhythmogenic Cardiomyopathy Involving Both Ventricles

“…The electrocardiography was characterized as a QRS wave duration ≥110 ms, inverted T waves in V 1 -V 3 leads, and completed left bundle brock [19]. In a Chinese cohort enrolling 90 subjects with ARVC/D, 5 patients carried the DSG2 p.F531C mutation [20]. In a Japanese family with ARVC, 2 probands carried compound DSP and DSG2 mutations (DSP p.K1582E and DSG2 p.F531C), whereas another member of this family, who satisfied 1 major criteria, carried only 1 mutation of DSP p.K1582E.…”

Arrhythmogenic Cardiomyopathy

“…The inheritance pattern of AC is more complex than previously appreciated, with frequent requirement for more than one 'hit' for fully penetrant disease [60,61,66,67]. The low penetrance of AC may be explained by a "recessive-like" inheritance pattern, based on the fact that AC probands often carry homozygous or compound heterozygous variants in the same gene, or digenic/oligogenic variants in a cluster of desmosomal genes.…”

“…Recent studies have shown that stop-coding in diseasecausing genes are more pathogenic than missense mutations, since the former are causing alteration of protein length and conformation, leading to haploinsufficiency due to protein instability [67][68][69][70]. Entire PKP2 exons or even whole gene deletions have been recently described in AC families with a frequency of approximately 2 % [71][72][73].…”

Cell Junctions in the Specialized Conduction System of the Heart

“…ARVC is a prime example of a cardiac disease associated with mutations/defects in desmosomal cell-cell junction components leading to defects in cardiac conduction, which include specific defects in the His-Purkinje system (Zusterzeel et al, 2013, Quarta et al, 2011, Bae et al, 2013, Bao et al, 2013, Cox et al, 2011) (Table 2). The electrophysiological criteria for diagnosing ARVC include epsilon waves, late potentials, prolonged terminal activation duration, ventricular tachycardia, and extrasystoles (Marcus et al, 2010).…”