Arrhythmogenic Right Ventricular Dysplasia/genetics* ; Genotype ; Humans ; Phenotype ; Risk Assessment

Desmoplakin (DSP), encoded by the DSP gene, is the main desmosome component and is abundant in the myocardial tissue. There are three DSP isoforms that assume the role of supporting structural stability through intercellular adhesion. It has been found that DSP regulates the transcription of adipogenic and fibrogenic genes, and maintains appropriate electrical conductivity by regulating gap junctions and ion channels. DSP is essential for normal myocardial development and the maintenance of its structural functions. Studies have suggested that DSP gene mutations are associated with a variety of hereditary cardiomyopathy, such as arrhythmia cardiomyopathy, dilated cardiomyopathy (DCM), left ventricular noncompaction, and is also closely associated with the Carvajal syndrome, Naxos disease, and erythro-keratodermia-cardiomyopathy syndrome with skin and heart damage. The structure and function of DSP, as well as the clinical manifestations of DSP-related cardiomyopathy were reviewed in this article.
Arrhythmogenic Right Ventricular Dysplasia ; Cardiomyopathies/genetics* ; Desmoplakins/genetics* ; Hair Diseases ; Humans ; Keratoderma, Palmoplantar

OBJECTIVE: To explore the clinical and genetic characteristics of a child with Arrhythmogenic right ventricular cardiomyopathy (ARVC). METHODS: A 6-year-old boy with ARVC who had visited Fujian Provincial Children's Hospital on August 23, 2022 was selected as the study subject. Relevant clinical data were collected, and peripheral venous blood samples were collected from the child and his parents for genetic testing through whole exome sequencing (WES). Sanger sequencing was carried out for family verification, and pathogenicity analysis was conducted for the candidate variants. RESULTS: The child had exhibited clinical symptoms including systemic edema, generalized heart enlargement, universal reduction of interventricular septum and ventricular wall movement, reduced left ventricular diastolic and systolic function, and reduced right ventricular systolic function. WES revealed that the child has harbored compound heterozygous variants of the PKP2 gene, namely c.119_122del (p.Leu40ArgfsTer71) and c.1978G>A (p.Gly660Arg), which were verified by Sanger sequencing to be respectively inherited from his father and mother. The c.119_122del variant has not been recorded in the 1000 Genomes, gnomAD and ExAC databases, and was predicted to lead to truncation of the PKP2 protein by SWISS-MODEL and PyMOL online software and classified as likely pathogenic based on the guidelines jointly developed by the American College of Medical Genetics and Genomics (ACMG) and ClinGen. The c.1978G>A variant has also not been recorded in the 1000 Genomes, gnomAD and ExAC databases, and was predicted to be deleterious by online software including REVEL, SIFT, CADD, Mutation Taster, and PolyPhen-2. The amino acid encoded by the variant site was highly conserved among various species by analysis using T-coffee and ESPript v3.0 online servers. The variant may affect the protein function by SWISS-MODEL and PyMOL online server analysis, and was classified as likely pathogenic based on the guidelines jointly developed by the ACMG and ClinGen. CONCLUSION The compound heterozygous variants of c.119_122del (p.Leu40ArgfsTer71) and c.1978G>A (p.Gly660Arg) of the PKP2 gene probably underlay the ARVC in this child. Above finding has broadened the spectrum of PKP2 gene variants and provided a reference for the diagnosis and genetic counseling.
Male ; Child ; Humans ; Arrhythmogenic Right Ventricular Dysplasia/genetics* ; Diastole ; Ethnicity ; Genetic Counseling ; Genetic Testing ; Plakophilins/genetics*

OBJECTIVE: To explore the correlation between DSG2, TTN and GATA4 genes and Brugada syndrome in Henan Province of China. METHODS: From February 2017 to February 2019, 100 patients with Brugada syndrome and 100 healthy individuals were selected as the study and the control groups, respectively. Electrocardiogram and echocardiography were carried out, and peripheral blood samples was collected. Coding regions of DSG2, TTN and GATA4 genes were amplified by PCR and sequenced. The results were compared with standard sequences from GenBank. RESULTS: Electrocardiogram showed that all patients from the study group had ventricular arrhythmia, 87 cases (87%) presented ventricular tachycardia (VT), 84 cases (84%) presented T wave inversion, and 51 cases (51%) presented Epsilon wave. Echocardiography showed that the right ventricle in the study group was enlarged with the inner diameter of the right ventricle being (40.0±13.3) mm, and the right ventricle showed various degree of abnormal systolic function. The enlargement of right atrium accounted for 64%, and the involvement of the left ventricle accounted for 27%. The right ventricular diameter and left ventricular diastolic diameter of the study group were significantly greater than those of the control group (P< 0.05). DNA sequencing showed that 60 patients carried DSG2 gene variants, among which 18 had missense variant of exon 8. Fifty patients carried TTN gene variants, including 8 in the A-band domain and 3 in the I-band domain. Twenty patients carried 3 variants of the GATA4 gene. CONCLUSION Variants of the DSG2, TTN and GATA4 genes in Henan region are correlated with the onset of Brugada syndrome.
Arrhythmogenic Right Ventricular Dysplasia ; Brugada Syndrome/genetics* ; China ; Connectin ; Desmoglein 2/genetics* ; GATA4 Transcription Factor ; Humans ; Pedigree ; Sequence Analysis, DNA

Objective To explore the association of cardiac disease associated genetic variants and the high incidence of Yunnan sudden unexplained death （YNSUD） in Yi nationality. Methods The genomic DNA was extracted from peripheral blood samples collected from 205 Yi villagers from YNSUD aggregative villages （inpatient group） and 197 healthy Yi villagers from neighboring villages （control group）. Fifty-two single nucleotide variants （SNVs） of 25 cardiac disease associated genes were genotyped using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS）. The SPSS 17.0 was used to analyze data. The pathogenicities of variants with differences between the two groups that have statistical significance were predicted by protein function prediction software PolyPhen-2 and SIFT. All villagers from inpatient group were given electrocardiogram （ECG） examination using a 12-lead electrocardiograph. Results The allele frequency and the genotype frequency of missense mutation DSG2 （rs2278792, c.2318G>A, p.R773K） of pathogenic genes of arrhythmogenic right ventricular cardiomyopathy （ARVC） in inpatient group was higher than that in control group （P<0.05）. Abnormal ECG changes were detected in 71 individuals （34.6%） in the inpatient group, among which 54 individuals carried R773K mutation, including clockwise （counterclockwise） rotation, left （right） axis deviation, ST segment and T wave alteration and heart-blocking. Conclusion Definite pathogenic mutations have not been found in the 52 cardiac disease genes associated SNVs detected in Yi nationality in regions with high incidence of YNSUD. The cause of high incidence of YNSUD in Yi nationality needs further study.
Arrhythmogenic Right Ventricular Dysplasia ; China/epidemiology* ; Death, Sudden/etiology* ; Death, Sudden, Cardiac/etiology* ; Ethnicity/genetics* ; Humans ; Incidence ; Mutation

OBJECTIVETo explore the linkage relationship between specific genetic markers and arrhythmogenic right ventricular cardiomyopathy (ARVC) in Chinese pedigrees.

METHODSThe microsatellite genetic markers D2S152, D14S252, and D10S1664 were studied for their linkages to ARVC in five Chinese ARVC pedigrees and a normal population of 121 Chinese individuals. Genomic DNA of the pedigrees and normal population was amplified using PCR techniques. Denaturing polyacrylamide sequencing gel (4%) electrophoresis was used to detect microsatellite repeat polymorphisms. Gels were silver-stained. A classical linkage analysis program was used assuming models of autosomal dominance and recession.

RESULTSThe logarithm of the odds (LOD) scores of D2S152 with ARVC in LW, WD, DS, LC and TY pedigrees were 2.174, -0.589, -infinity, - (indicating that linkage is not supported in this mode), and -infinity respectively in autosomal dominant model (recombination fraction = 0.000 respectively)and were -infinity, -infinity, -infinity, -infinity, and 0.182 respectively in the autosomal recessive model. The LOD scores of D14S252 with ARVC in LW, WD, DS, LC and TY pedigrees were -, -, -infinity, -, and 0 respectively in autosomal dominant model, and were -infinity, -0.812, -infinity, -infinity, and 0.087 respectively in autosomal recessive model. The LOD scores of D2S152 with ARVC in LW, WD, DS, LC and TY pedigrees were -, -0.539, -, and 0.602 respectively in autosomal dominant model and were -, -infinity, -infinity, -infinity, and - infinity respectively in autosomal recessive model.

CONCLUSIONSThe LOD score for D2S152 in the LW pedigree was 2.174, indicating that the chance of linkage is about 150:1. This suggests that there is a possible ARVC-related gene near this marker. There were no clear linkage relationships between ARVC and D10S1664 and D14S252 in this family, and no linkages between ARVC and any of the three genetic markers in the other four families. These results also suggest that there is genetic heterogeneity in LW and in the other pedigrees.

Arrhythmogenic Right Ventricular Dysplasia ; genetics ; Asian Continental Ancestry Group ; China ; Female ; Genetic Linkage ; Genetic Markers ; Humans ; Lod Score ; Male ; Microsatellite Repeats

BACKGROUNDArrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable cardiac disease predominantly caused by mutations in desmosomal protein genes. Previous genetic analyses of the Chinese ARVC population are limited to small size and restriction to a single gene. This study was aimed to investigate the genotype in a large series of Chinese patients with ARVC through comprehensively screening nine ARVC-causing genes.

METHODSA total of 100 unrelated ARVC patients and 300 age, gender and ethnicity matched healthy controls were genetically tested with multiplexing targeted resequencing for nine previously reported ARVC-causing genes, including plakophilin-2, desmoplakin, desmoglein-2, desmocollin-2, plakoglobin, transforming growth factor beta-3, transmembrane protein 43, desmin and Lamin A/C.

RESULTSFifty-nine mutations were identified in 64% of the patients, among which, 93% were located in desmosomal protein genes. Plakophilin-2 mutations accounted for 54% of the total and 58% of the desmosomal mutations, with a truncating mutation type making up about 2/3 of the plakophilin-2 mutations. Only four mutations were found in non-desmosomal genes; two in transmembrane protein 43 and two in transforming growth factor beta-3. Two of them (one of each gene) appeared as single missense mutations. No mutation was identified in desmin or Lamin A/C. Multiple mutations were found in 23% of the patients, with plakophilin-2 being found in 57% of the multi-mutation carriers.

CONCLUSIONSPlakophilin-2 was the most common gene mutation that was identified in Chinese ARVC patients. Non-desmosomal genes should be added to desmosomal protein genes when performing molecular genetic screening in patients with suspected ARVC.

Adult ; Arrhythmogenic Right Ventricular Dysplasia ; genetics ; metabolism ; Asian Continental Ancestry Group ; Desmin ; genetics ; Desmoglein 2 ; genetics ; Female ; Humans ; Male ; Middle Aged ; Mutation ; Plakophilins ; genetics ; Young Adult ; gamma Catenin ; genetics

BACKGROUNDArrhythmogenic right ventricular cardiomyopathy (ARVC) is one of the leading causes of sudden cardiac death. Recent studies have shown that ARVC, which is an inheritable genetic change, results from mutations in genes encoding desmosomal proteins. Plakophilin-2 is an important component of the desmosome. Because the full range of genetic variations related to ARVC is unknown and no related studies of the Chinese population have been reported, we aimed to investigate the genetic variation of plakophilin-2 in ARVC patients from the Southern Region of China.

METHODSGenomic DNA was isolated from peripheral blood samples of all 34 ARVC patients, who were screened through a clinical evaluation. They were used to detect variations in the sequences of the plakophilin-2 genes by polymerase chain reaction amplification in combination with direct sequencing.

RESULTSIn exon-1 of the plakophilin-2 gene, a deletion mutation (c.145_148 del GACA) was found in one family pedigree. The mutation was also found in exon-2, 4, and 11 of the plakophilin-2 gene. The QT interval dispersion of the ECG was considerably longer in the mutation group than in the non-mutation group of ARVC patients, and this result was statistically significant (P < 0.05).

CONCLUSIONWe discovered a plakophilin-2 mutation that prolongs the QT interval dispersion in the southern Chinese ARVC population.

Adult ; Arrhythmogenic Right Ventricular Dysplasia ; genetics ; Asian Continental Ancestry Group ; genetics ; Child ; China ; DNA Mutational Analysis ; Exons ; genetics ; Genetic Predisposition to Disease ; Humans ; Male ; Middle Aged ; Mutation ; Pedigree ; Plakophilins ; genetics