12-32878511-C-T

Variant names:

• chr12-32878511-C-T
• rs774663443
• NM_001005242.3:c.369G>A

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.369G>A​(p.Trp123*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PKP2 NM_001005242.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:7
• Conservation: PhyloP100: 2.15

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]

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 12-32878511-C-T is Pathogenic according to our data. Variant chr12-32878511-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 201970.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PKP2	NM_001005242.3	c.369G>A	p.Trp123*	stop_gained	Exon 3 of 13	ENST00000340811.9	NP_001005242.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PKP2	ENST00000340811.9	c.369G>A	p.Trp123*	stop_gained	Exon 3 of 13	1	NM_001005242.3	ENSP00000342800.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000403 AC: 1 AN: 248426 Hom.: 0 AF XY: 0.00000743 AC XY: 1 AN XY: 134502

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000891

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Arrhythmogenic right ventricular dysplasia 9 Pathogenic:4

Nov 12, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 29, 2019

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 08, 2024

Institute of Human Genetics, Heidelberg University

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 14, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Trp123*) in the PKP2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PKP2 are known to be pathogenic (PMID: 15489853, 17041889, 23911551). This variant is present in population databases (rs774663443, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with clinical features of arrhythmogenic right ventricular cardiomyopathy (PMID: 22035158, 28600387). ClinVar contains an entry for this variant (Variation ID: 201970). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:2

Jul 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PKP2: PVS1, PM2, PS4:Moderate, PP4 -

Nov 30, 2021

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in association with arrhythmogenic right ventricular cardiomyopathy (ARVC) and inherited cardiomyopathy in the published literature (van Lint et al., 2019; Marschall et al., 2019; Kolokotronis et al., 2020); Not observed at significant frequency in large population cohorts (Lek et al., 2016); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Reported in ClinVar (ClinVar Variant ID#201970; Landrum et al., 2016); This variant is associated with the following publications: (PMID: 31386562, 31737537, 32659924, 34816084, 32615795) -

Cardiovascular phenotype Pathogenic:1

May 07, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.W123* pathogenic mutation (also known as c.369G>A), located in coding exon 3 of the PKP2 gene, results from a G to A substitution at nucleotide position 369. This changes the amino acid from a tryptophan to a stop codon within coding exon 3. A different nucleotide change resulting in the same protein impact (c.368G>A, p.W123*) has been reported in individuals with arrhythmogenic right ventricular cardiomyopathy (ARVC) and affected family members (Aneq MÅ et al. Scand. Cardiovasc. J., 2012 Apr;46:72-5; Mellor G et al. Circ Cardiovasc Genet, 2017 Jun;10). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, 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

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Uncertain	0.87	D
Vest4		0.53
GERP RS		4.0

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: rs774663443; hg19: chr12-33031445;