12-32877928-G-GCGCTCTCCTCCCGCTGGAATCCA

Position:

• chr12-32877928-G-GCGCTCTCCTCCCGCTGGAATCCA

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001005242.3(PKP2):​c.951_952insTGGATTCCAGCGGGAGGAGAGCG​(p.His318TrpfsTer10) 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 Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. A317A) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PKP2 NM_001005242.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -1.26

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 12 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 12-32877928-G-GCGCTCTCCTCCCGCTGGAATCCA is Pathogenic according to our data. Variant chr12-32877928-G-GCGCTCTCCTCCCGCTGGAATCCA is described in ClinVar as [Pathogenic]. Clinvar id is 406552.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PKP2	NM_001005242.3	c.951_952insTGGATTCCAGCGGGAGGAGAGCG	p.His318TrpfsTer10	frameshift_variant	3/13	ENST00000340811.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PKP2	ENST00000340811.9	c.951_952insTGGATTCCAGCGGGAGGAGAGCG	p.His318TrpfsTer10	frameshift_variant	3/13	1	NM_001005242.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250864 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135632

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: 0.00000883

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Arrhythmogenic right ventricular dysplasia 9 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2019

For these reasons, this variant has been classified as Pathogenic. While this particular variant has not been reported in the literature, loss-of-function variants in PKP2 are known to be pathogenic (PMID: 15489853). This sequence change inserts 23 nucleotides in exon 3 of the PKP2 mRNA (c.929_951dup23), causing a frameshift at codon 318. This creates a premature translational stop signal (p.His318Trpfs*10) and is expected to result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1064792927; hg19: chr12-33030862;