chr12-32850873-A-G

Variant names:

• chr12-32850873-A-G
• rs397516990
• NM_001005242.3:c.1271T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001005242.3(PKP2):​c.1271T>C​(p.Phe424Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,706 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F424I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PKP2 NM_001005242.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts P:1 U:2
• Conservation: PhyloP100: 2.33
• Publications: 5 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.96

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PKP2	NM_001005242.3	c.1271T>C	p.Phe424Ser	missense_variant	Exon 5 of 13	ENST00000340811.9	NP_001005242.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PKP2	ENST00000340811.9	c.1271T>C	p.Phe424Ser	missense_variant	Exon 5 of 13	1	NM_001005242.3	ENSP00000342800.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461706 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727156

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44716

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111882

Other (OTH) AF: 0.00 AC: 0 AN: 60376

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Arrhythmogenic right ventricular cardiomyopathy Pathogenic:1 Uncertain:1

Jul 29, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 18, 2009

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Cardiovascular phenotype Uncertain:1

Jun 28, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.F424S variant (also known as c.1271T>C), located in coding exon 5 of the PKP2 gene, results from a T to C substitution at nucleotide position 1271. The phenylalanine at codon 424 is replaced by serine, an amino acid with highly dissimilar properties. This variant has been detected in individuals with features consistent with arrhythmogenic right ventricular cardiomyopathy (Dalal D et al. J Am Coll Cardiol, 2006 Oct;48:1416-24; Dalal D et al. Circulation, 2006 Apr;113:1641-9; Tan BY et al. J Cardiovasc Transl Res, 2010 Dec;3:663-73; Asimaki A et al. Circ Arrhythm Electrophysiol, 2016 Feb;9:e003688; Orgeron GM et al. J Am Heart Assoc, 2017 Jun;6). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.49	.;T
Eigen	Uncertain	0.56
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Benign	0.85	D;D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.96	D;D
MetaSVM	Benign	-0.58	T
MutationAssessor	Uncertain	2.3	M;M
PhyloP100		2.3
PrimateAI	Uncertain	0.68	T
PROVEAN	Pathogenic	-6.2	D;D
REVEL	Uncertain	0.56
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0010	D;D
Polyphen		1.0	D;D
Vest4		0.67
MutPred		0.88		Gain of disorder (P = 0.0057);Gain of disorder (P = 0.0057);
MVP		0.78
MPC		0.89
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.94
gMVP		0.63
Mutation Taster		=6/94	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs397516990; hg19: chr12-33003807;