12-32821473-C-T

Variant names:

• chr12-32821473-C-T
• rs193922673
• NM_001005242.3:c.1896G>A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001005242.3(PKP2):​c.1896G>A​(p.Trp632*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,794 control chromosomes in the GnomAD database, with no homozygous occurrence. 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)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PKP2 NM_001005242.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 0.700
• Publications: 4 publications found

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 Gene-Disease associations (from GenCC):

• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• arrhythmogenic right ventricular dysplasia 9

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• left ventricular noncompaction

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Brugada syndrome

  Inheritance: AD Classification: LIMITED Submitted by: Genomics England PanelApp
• Brugada syndrome 1

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• catecholaminergic polymorphic ventricular tachycardia

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• dilated cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 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 12-32821473-C-T is Pathogenic according to our data. Variant chr12-32821473-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 36682.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.1896G>A	p.Trp632*	stop_gained	Exon 9 of 13	ENST00000340811.9	NP_001005242.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PKP2	ENST00000340811.9	c.1896G>A	p.Trp632*	stop_gained	Exon 9 of 13	1	NM_001005242.3	ENSP00000342800.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461794 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727198

African (AFR) AF: 0.0000299 AC: 1 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111930

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Arrhythmogenic right ventricular dysplasia 9 Pathogenic:2

Dec 29, 2024

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.Trp676*) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with arrhythmogenic right ventricular cardiomyopathy (ARVC) (PMID: 16567567, 31386562). ClinVar contains an entry for this variant (Variation ID: 36682). For these reasons, this variant has been classified as Pathogenic. -

Jan 23, 2018

HudsonAlpha Institute for Biotechnology, HudsonAlpha Institute for Biotechnology

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

not provided Pathogenic:1

Jun 21, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in ClinVar as pathogenic or likely pathogenic but additional evidence is not available (ClinVar Variant ID# 36682; ClinVar); 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; Not observed in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25525159, 20031616, 16567567, 21606390, 25820315, 21606396, 31402444, 31386562) -

Familial isolated arrhythmogenic right ventricular dysplasia Pathogenic:1

May 23, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PKP2 c.2028G>A (p.Trp676X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 251646 control chromosomes. c.2028G>A has been observed in individual(s) affected with Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (vanTintelen_2006). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 16567567, 20031616). ClinVar contains an entry for this variant (Variation ID: 36682). Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	40
DANN	Uncertain	1.0
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.83	D
PhyloP100		0.70
Vest4		0.83
GERP RS		4.9
Mutation Taster		=1/199	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs193922673; hg19: chr12-32974407;