rs387906802

Positions:

• chr8-143923055-G-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_201384.3(PLEC):​c.6874C>T​(p.Arg2292*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,458,394 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 (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: PLEC NM_201384.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 2.86

Genes affected

PLEC (HGNC:9069): (plectin) Plectin is a prominent member of an important family of structurally and in part functionally related proteins, termed plakins or cytolinkers, that are capable of interlinking different elements of the cytoskeleton. Plakins, with their multi-domain structure and enormous size, not only play crucial roles in maintaining cell and tissue integrity and orchestrating dynamic changes in cytoarchitecture and cell shape, but also serve as scaffolding platforms for the assembly, positioning, and regulation of signaling complexes (reviewed in PMID: 9701547, 11854008, and 17499243). Plectin is expressed as several protein isoforms in a wide range of cell types and tissues from a single gene located on chromosome 8 in humans (PMID: 8633055, 8698233). Until 2010, this locus was named plectin 1 (symbol PLEC1 in human; Plec1 in mouse and rat) and the gene product had been referred to as "hemidesmosomal protein 1" or "plectin 1, intermediate filament binding 500kDa". These names were superseded by plectin. The plectin gene locus in mouse on chromosome 15 has been analyzed in detail (PMID: 10556294, 14559777), revealing a genomic exon-intron organization with well over 40 exons spanning over 62 kb and an unusual 5' transcript complexity of plectin isoforms. Eleven exons (1-1j) have been identified that alternatively splice directly into a common exon 2 which is the first exon to encode plectin's highly conserved actin binding domain (ABD). Three additional exons (-1, 0a, and 0) splice into an alternative first coding exon (1c), and two additional exons (2alpha and 3alpha) are optionally spliced within the exons encoding the acting binding domain (exons 2-8). Analysis of the human locus has identified eight of the eleven alternative 5' exons found in mouse and rat (PMID: 14672974); exons 1i, 1j and 1h have not been confirmed in human. Furthermore, isoforms lacking the central rod domain encoded by exon 31 have been detected in mouse (PMID:10556294), rat (PMID: 9177781), and human (PMID: 11441066, 10780662, 20052759). The short alternative amino-terminal sequences encoded by the different first exons direct the targeting of the various isoforms to distinct subcellular locations (PMID: 14559777). As the expression of specific plectin isoforms was found to be dependent on cell type (tissue) and stage of development (PMID: 10556294, 12542521, 17389230) it appears that each cell type (tissue) contains a unique set (proportion and composition) of plectin isoforms, as if custom-made for specific requirements of the particular cells. Concordantly, individual isoforms were found to carry out distinct and specific functions (PMID: 14559777, 12542521, 18541706). In 1996, a number of groups reported that patients suffering from epidermolysis bullosa simplex with muscular dystrophy (EBS-MD) lacked plectin expression in skin and muscle tissues due to defects in the plectin gene (PMID: 8698233, 8941634, 8636409, 8894687, 8696340). Two other subtypes of plectin-related EBS have been described: EBS-pyloric atresia (PA) and EBS-Ogna. For reviews of plectin-related diseases see PMID: 15810881, 19945614. Mutations in the plectin gene related to human diseases should be named based on the position in NM_000445 (variant 1, isoform 1c), unless the mutation is located within one of the other alternative first exons, in which case the position in the respective Reference Sequence should be used. [provided by RefSeq, Aug 2011]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 10 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-143923055-G-A is Pathogenic according to our data. Variant chr8-143923055-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 30174.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr8-143923055-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PLEC	NM_201384.3	c.6874C>T	p.Arg2292*	stop_gained	31/32	ENST00000345136.8	NP_958786.1
PLEC	NM_201378.4	c.6832C>T	p.Arg2278*	stop_gained	31/32	ENST00000356346.7	NP_958780.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PLEC	ENST00000345136.8	c.6874C>T	p.Arg2292*	stop_gained	31/32	1	NM_201384.3	ENSP00000344848.3
PLEC	ENST00000356346.7	c.6832C>T	p.Arg2278*	stop_gained	31/32	1	NM_201378.4	ENSP00000348702.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000207 AC: 5 AN: 241484 Hom.: 0 AF XY: 0.0000302 AC XY: 4 AN XY: 132530

Gnomad AFR exome AF: 0.0000697

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000561

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000275

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000130 AC: 19 AN: 1458394 Hom.: 0 Cov.: 70 AF XY: 0.0000179 AC XY: 13 AN XY: 725634

Gnomad4 AFR exome AF: 0.0000598

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000153

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000497 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Feb 04, 2019	The R2319X variant in the PLEC gene has been reported previously in the homozygous or compound heterozygous state in multiple individuals with epidermolysis bullosa (EB) with muscular dystrophy (EBS-MD) and also in one patient with EBS-MD and myasthenic syndrome (Takahashi et al., 2005; Yin et al., 2015; Vahidnezhad et al., 2017; Selcen et al., 2011). This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The R2319X variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). We interpret R2319X as a pathogenic variant. -

Epidermolysis bullosa simplex with nail dystrophy Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jan 25, 2011

- -

Epidermolysis bullosa simplex, Ogna type;C2677349:Epidermolysis bullosa simplex 5C, with pyloric atresia;C2931072:Epidermolysis bullosa simplex 5B, with muscular dystrophy;C3150989:Autosomal recessive limb-girdle muscular dystrophy type 2Q;C4225309:Epidermolysis bullosa simplex with nail dystrophy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 20, 2022

This variant is present in population databases (rs387906802, gnomAD 0.007%). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 30174). This premature translational stop signal has been observed in individuals with autosomal recessive epidermolysis bullosa simplex with muscular dystrophy (PMID: 15659326, 28830826). This sequence change creates a premature translational stop signal (p.Arg2319*) in the PLEC gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PLEC are known to be pathogenic (PMID: 20301336, 20447487, 21109228, 23289980, 28824526). -

Epidermolysis bullosa simplex 5B, with muscular dystrophy Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jan 25, 2011

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	41
DANN	Uncertain	0.99
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Uncertain	0.93	D
Vest4		0.84
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2

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: rs387906802; hg19: chr8-144997223; COSMIC: COSV59707009;