12-32843177-C-T

Variant names:

• chr12-32843177-C-T
• rs779392697
• NM_001005242.3:c.1379-1972G>A

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 0P and 8B. BP4_Strong BS2

The NM_004572.4(PKP2):​c.1510+5G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000246 in 488,124 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000021 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000026 (0 hom.)
• Consequence: PKP2 NM_004572.4 splice_region, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8 B:1
• Conservation: PhyloP100: -0.432

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 Benign. Variant got -8 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.87).
• BS2: High AC in GnomAdExome4 at 9 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PKP2	NM_001005242.3	c.1379-1972G>A		intron_variant	Intron 5 of 12	ENST00000340811.9	NP_001005242.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PKP2	ENST00000340811.9	c.1379-1972G>A		intron_variant	Intron 5 of 12	1	NM_001005242.3	ENSP00000342800.5

Frequencies

GnomAD3 genomes AF: 0.0000205 AC: 3 AN: 146106 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000687

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000301

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000110 AC: 2 AN: 181044 Hom.: 0 AF XY: 0.0000202 AC XY: 2 AN XY: 98826

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: 0.0000254

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000263 AC: 9 AN: 342018 Hom.: 0 Cov.: 4 AF XY: 0.0000360 AC XY: 7 AN XY: 194360

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000331

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000158

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000383

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000205 AC: 3 AN: 146106 Hom.: 0 Cov.: 32 AF XY: 0.0000281 AC XY: 2 AN XY: 71232

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000687

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000301

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:8 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:3

-

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

-

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

-

Breakthrough Genomics, Breakthrough Genomics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

not specified Uncertain:2

Dec 29, 2017

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1510+5G>A variant in PKP2 has not been reported in the literature, but was identified in 3/27754 of Latino and 3/91752 of European chromosomes by the Geno me Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs77939 2697). This variant has also been reported in ClinVar (Variation ID:239953). Thi s variant is located in the 5' splice region. Computational tools suggest some i mpact to splicing. However, this information is not predictive enough to determi ne pathogenicity. In summary, the clinical significance of the c.1510+5G>A varia nt is uncertain. ACMG/AMP Criteria applied: PP3. -

Nov 15, 2021

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PKP2 c.1510+5G>A alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Two predict the variant abolishes the canonical 5' splicing donor site. Two predict the variant weakens the canonical 5' splice donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.1e-05 in 181044 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1510+5G>A has been reported in the literature in a study of individuals enrolled in MyCode Community Health Initiative of Geisinger Health System (GHS), an IRB-approved research biorepository and precision medicine project (Haggerty_2017). These report(s) do not provide unequivocal conclusions about association of the variant with Cardiomyopathy. At-least two co-occurrences with other pathogenic variant(s) have been reported at our laboratory (HCM-MYBPC3 c.1505G>A, p.Arg502Gln; ARVD-PKP2 c.2509delA, p.Ser837fs), providing supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -

Cardiomyopathy Uncertain:2

May 28, 2021

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 10, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes a G>A nucleotide substitution at the +5 position of intron 6 of the PKP2 gene. Splice site prediction tools predict that this variant may have a significant impact on RNA splicing. To our knowledge, RNA studies have not been performed for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 5/211564 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Arrhythmogenic right ventricular dysplasia 9 Uncertain:1

Oct 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 6 of the PKP2 gene. It does not directly change the encoded amino acid sequence of the PKP2 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs779392697, gnomAD 0.01%). This variant has been observed in individual(s) with dilated cardiomyopathy and/or arrhythmogenic cardiomyopathy (PMID: 32826072, 35819174). ClinVar contains an entry for this variant (Variation ID: 239953). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Cardiovascular phenotype Benign:1

Oct 18, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.87
CADD	Benign	6.2
DANN	Benign	0.58

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Benign	0.72
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: rs779392697; hg19: chr12-32996111;