rs1555144459

Positions:

• chr12-32841038-C-CA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001005242.3(PKP2):​c.1545dupT​(p.Gly516fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PKP2 NM_001005242.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: -0.633

Genes affected

PKP2 (HGNC:9024): (plakophilin 2) This gene encodes a member of the arm-repeat (armadillo) and plakophilin gene families. Plakophilin proteins contain numerous armadillo repeats, localize to cell desmosomes and nuclei, and participate in linking cadherins to intermediate filaments in the cytoskeleton. This gene may regulate the signaling activity of beta-catenin and is required to maintain transcription of genes that control intracellular calcium cycling including ryanodine receptor 2, ankyrin-B, triadin, and calcium channel, voltage-dependent, L type, alpha 1C. Mutations in this gene are associated with different inherited cardiac conditions including Arrythmogenic Cardiomyopathy, Brugada Syndrome, and Idiopathic Ventricular Fibrillation. A processed pseudogene with high similarity to this gene has been mapped to chromosome 12p13. [provided by RefSeq, May 2022]

PKP2 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-32841038-C-CA is Pathogenic according to our data. Variant chr12-32841038-C-CA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 517335.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PKP2	NM_001005242.3	c.1545dupT	p.Gly516fs	frameshift_variant	6/13	ENST00000340811.9	NP_001005242.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PKP2	ENST00000340811.9	c.1545dupT	p.Gly516fs	frameshift_variant	6/13	1	NM_001005242.3	ENSP00000342800.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Arrhythmogenic right ventricular dysplasia 9 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing;provider interpretation	Geisinger Autism and Developmental Medicine Institute, Geisinger Health System	Nov 27, 2017	This 6 year old male with autism spectrum disorder was found to carry a paternally-inherited expected pathogenic variant in the PKP2 gene, which confers an increased risk of developing arrhythmogenic right ventricular cardiomyopathy. Given his age, we would not expect him to exhibit any features of the condition at this time, though a cardiac evaluation is pending. The patient's father's cardiac MRI has thus far been normal; he is 31 years old at time of report and cardiac evaluation. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 12, 2019	This sequence change creates a premature translational stop signal (p.Gly560Trpfs*12) in the PKP2 gene. It is expected to result in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in PKP2 are known to be pathogenic (PMID: 15489853, 23911551). This variant has not been reported in the literature in individuals with PKP2-related disease. ClinVar contains an entry for this variant (Variation ID: 517335). This variant is not present in population databases (ExAC no frequency). -

Cardiomyopathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Apr 28, 2017

The p.Gly560fs variant in PKP2 has not been previously reported in individuals w ith cardiomyopathy or in large population studies, though the ability of these s tudies to accurately detect indels may be limited. This variant is predicted to cause a frameshift, which alters the protein?s amino acid sequence beginning at position 560 and leads to a premature termination codon 12 amino acids downstrea m. This alteration is then predicted to lead to a truncated or absent protein. F rameshift and other truncating variants in PKP2 are strongly associated with arr hythmogenic right ventricular cardiomyopathy. In summary, although additional st udies are required to fully establish its clinical significance, the p.Gly560fs variant is likely pathogenic. -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

May 26, 2023

The c.1677dupT pathogenic mutation, located in coding exon 7 of the PKP2 gene, results from a duplication of T at nucleotide position 1677, causing a translational frameshift with a predicted alternate stop codon (p.G560Wfs*12). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555144459; hg19: chr12-32993972;