PKP2 Mutation Analysis
Plakophilins are armadillo repeat-containing proteins that localize in the desmosomal plaque and cell nucleus. The desmosomal plakophilin 2, encoded by the PKP2 gene, forms part of the link between the cytoplasmic tail of cadherins and the intermediate filament cytoskeleton, may regulate the signaling activity of beta-catenin. PKP2 gene contains 14 exons and spans around 106 kb genomic distance that was mapped to chromosome 12p11.21. A processed pseudogene with high similarity to this locus has been mapped to chromosome 12p13. Alternatively spliced transcripts encoding two distinct protein isoforms have been identified. Mutations in PKP2 gene are associated with arrhythmogenic right ventricular dysplasia/cardiomyopathy type 9 (ARVD/C9). ARVD/C is an autosomal dominant disease characterized by partial degeneration of the myocardium of the right ventricle, electrical instability and sudden death. Definitive genotype/phenotype correlations have not been described.
The John Welsh Cardiovascular Diagnostic Laboratory offers molecular genetic testing for PKP2 mutations. Individuals are tested by automatic fluorescent DNA sequencing of the coding exons of the PKP2 gene. We strongly recommend initial testing of a clearly affected individual, if available, in order to provide the greatest test sensitivity and clearest interpretation of results for subsequent family members. Genetic counseling is recommended for all individuals.
Reasons for Referral
Molecular confirmation of the diagnosis of familial arrhythmogenic right ventricular dysplasia/cardiomyopathy type 9 (ARVD/C9).
Genomic DNA is analyzed for PKP2 mutations by automatic fluorescent DNA sequencing of the coding exons of the PKP2 gene, as well as the exon/intron junctions and a portion of the 5' and 3' untranslated regions. Patient DNA is sequenced in both the forward and reverse orientations. If a mutation is identified, additional family members are analyzed only for the familial mutation by automatic fluorescent DNA sequencing.
|Service||Direct and Institutional Billing||CPT Codes|
|Index Case (Full Gene)||$1100 per sample||81406, G0452|
|Additional Family Members||$300 per sample; known familial mutation only||81403, G0452|
DNA Sequencing Analysis: Approximately 99 percent detection of mutations in coding exons 1-14 of PKP2.
Blood (preferred): EDTA (purple-top) tubes: Adult: 5 cc, Child: 5 cc, Infant: 2-3 cc
Tissue: Frozen (preferred), RNAlater, Formalin-fixed, Paraffin-embedded
Other Body Fluids: Call to inquire
Buccal Swabs: One swab from each cheek