Alternative titles; symbols
ORPHA: 217656; DO: 0110077;
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
Gene/Locus |
Gene/Locus MIM number |
|---|---|---|---|---|---|---|
| 12p11.21 | Arrhythmogenic right ventricular dysplasia 9 | 609040 | Autosomal dominant | 3 | PKP2 | 602861 |
A number sign (#) is used with this entry because of evidence that familial arrhythmogenic right ventricular dysplasia-9 (ARVD9) is caused by heterozygous mutations in the PKP2 gene (602861), which encodes plakophilin-2, an essential armadillo repeat protein of the cardiac desmosome, on chromosome 12p11.
For phenotypic information and evidence of genetic heterogeneity in this disorder, see ARVD1 (107970).
On the basis of findings of a lethal defect in cardiac morphogenesis at embryonic day 10.75 in mice homozygous with respect to a deletion mutation of Pkp2 (Grossmann et al., 2004), Gerull et al. (2004) hypothesized that mutations in human PKP2 may account for ARVC. They collected samples from a total of 120 unrelated ARVC probands of Western European descent (101 males and 19 females) who were diagnosed using criteria proposed by McKenna et al. (1994). Gerull et al. (2004) sequenced all 14 PKP exons, including flanking intronic splice sequences, and identified 25 different heterozygous mutations in 32 probands (27 males and 5 females) (see, e.g., 602861.0001-602861.0004).
Gerull et al. (2004) stated that inasmuch as mutations causing ARVC have been identified in PKP2, JUP (encoding plakoglobin; 173325), and DSP (encoding desmoplakin; 125647), ARVC may be considered a disease of the desmosome. Desmosomes are complex multiprotein structures of the cell membrane and provide structural and functional integrity to adjacent cells (e.g., epithelial cells and cardiomyocytes). Desmosomal proteins also have a role in cell signaling. At least 3 groups of molecules contribute to the formation of desmosomes: desmosomal cadherins, armadillo-repeat proteins, and plakophilins. The plakophilins, which are armadillo-related proteins, contain 10 42-amino acid armadillo repeat motifs and are located in the outer dense plaque of desmosomes, linking desmosomal cadherins with desmoplakin and the intermediate filament system. Like other armadillo-repeat proteins, plakophilins are also found in the nucleus, where they may have a role in transcriptional regulation. Plakophilin-2 (PKP2; 602861) exists in 2 alternatively spliced isoforms (2a and 2b), interacts with multiple other cell adhesion proteins, and is the primary cardiac plakophilin (Mertens et al., 2001).
Dalal et al. (2006) confirmed high prevalence of PKP2 mutations in a large cohort of patients with ARVD/C and reported that those with PKP2 mutations present with arrhythmia earlier than do patients with ARVD/C who do not have a PKP2 mutation.
Kim et al. (2013) generated induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) from 2 patients with ARVD/C carrying PKP2 mutations (ARVD9). Mutant PKP2 iPSC-CMs demonstrated abnormal plakoglobin nuclear translocation and decreased beta-catenin (CTNNB1; 116806) activity in cardiogenic conditions; however, these abnormal features were insufficient to reproduce the pathologic phenotypes of ARVD/C in standard cardiogenic conditions. Kim et al. (2013) showed that induction of adult-like metabolic energetics from an embryonic/glycolytic state and abnormal PPAR-gamma (PPARG; 601487) activation underlie the pathogenesis of ARVD/C. By coactivating normal PPAR-alpha (PPARA; 170998)-dependent metabolism and an abnormal PPAR-gamma pathway in beating embryoid bodies with defined media, Kim et al. (2013) established an efficient ARVD/C in vitro model within 2 months. This model manifested exaggerated lipogenesis and apoptosis in mutant PKP2 iPSC-CMs. iPSC-CMs with a homozygous PKP2 mutation also had calcium-handling deficits. Kim et al. (2013) concluded that their study was the first to demonstrate that induction of adult-like metabolism has a critical role in establishing an adult-onset disease model using patient-specific iPSCs. Their model also revealed that metabolic derangement in an adult-like metabolic milieu underlies ARVD/C pathologies, enabling the proposal of novel therapeutic strategies.
Dalal, D., Molin, L. H., Piccini, J., Tichnell, C., James, C., Bomma, C., Prakasa, K., Towbin, J. A., Marcus, F. I., Spevak, P. J., Bluemke, D. A., Abraham, T., Russell, S. D., Calkins, H., Judge, D. P. Clinical features of arrhythmogenic right ventricular dysplasia/cardiomyopathy associated with mutations in plakophilin-2. Circulation 113: 1641-1649, 2006. [PubMed: 16549640] [Full Text: https://doi.org/10.1161/CIRCULATIONAHA.105.568642]
Gerull, B., Heuser, A., Wichter, T., Paul, M., Basson, C. T., McDermott, D. A., Lerman, B. B., Markowitz, S. M., Ellinor, P. T., MacRae, C. A., Peters, S., Grossmann, K. S., Michely, B., Sasse-Klaassen, S., Birchmeier, W., Dietz, R., Breithardt, G., Schulze-Bahr, E., Thierfelder, L. Mutations in the desmosomal protein plakophilin-2 are common in arrhythmogenic right ventricular cardiomyopathy. Nature Genet. 36: 1162-1164, 2004. Note: Erratum: Nature Genet. 37: 106 only, 2005. [PubMed: 15489853] [Full Text: https://doi.org/10.1038/ng1461]
Grossmann, K. S., Grund, C., Huelsken, J., Behrend, M., Erdmann, B., Franke, W. W., Birchmeier, W. Requirement of plakophilin 2 for heart morphogenesis and cardiac junction formation. J. Cell Biol. 167: 149-160, 2004. [PubMed: 15479741] [Full Text: https://doi.org/10.1083/jcb.200402096]
Kim, C., Wong, J., Wen, J., Wang, S., Wang, C., Spiering, S., Kan, N. G., Forcales, S., Puri, P. L., Leone, T. C., Marine, J. E., Calkins, H., Kelly, D. P., Judge, D. P., Chen, H.-S. V. Studying arrhythmogenic right ventricular dysplasia with patient-specific iPSCs. Nature 494: 105-110, 2013. [PubMed: 23354045] [Full Text: https://doi.org/10.1038/nature11799]
McKenna, W. J., Thiene, G., Nava, A., Fontaliran, F., Blomstrom-Lundqvist, C., Fontaine, G., Camerini, F. Diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy: task force of the working group myocardial and pericardial disease of the European Society of Cardiology and of the Scientific Council on Cardiomyopathies of the International Society and Federation of Cardiology. Brit. Heart J. 71: 215-218, 1994. [PubMed: 8142187] [Full Text: https://doi.org/10.1136/hrt.71.3.215]
Mertens, C., Hofmann, I., Wang, Z., Teichmann, M., Sepehri Chong, S., Schnolzer, M., Franke, W. W. Nuclear particles containing RNA polymerase III complexes associated with the junctional plaque protein plakophilin 2. Proc. Nat. Acad. Sci. 98: 7795-7800, 2001. [PubMed: 11416169] [Full Text: https://doi.org/10.1073/pnas.141219498]