8-143923615-GC-AT

Position:

• chr8-143923615-GC-AT

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP6

The NM_201384.3(PLEC):​c.6313_6314delinsAT​(p.Ala2105Met) variant causes a missense 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A2105T) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 34)
• Consequence: PLEC NM_201384.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:2
• Conservation: PhyloP100: 2.30

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 These names were superseded by plectin.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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 8-143923615-GC-AT is Benign according to our data. Variant chr8-143923615-GC-AT is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 281942.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=3}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PLEC	NM_201378.4	c.6271_6272delinsAT	p.Ala2091Met	missense_variant	31/32	ENST00000356346.7
PLEC	NM_201384.3	c.6313_6314delinsAT	p.Ala2105Met	missense_variant	31/32	ENST00000345136.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PLEC	ENST00000345136.8	c.6313_6314delinsAT	p.Ala2105Met	missense_variant	31/32	1	NM_201384.3
PLEC	ENST00000356346.7	c.6271_6272delinsAT	p.Ala2091Met	missense_variant	31/32	1	NM_201378.4

Frequencies

GnomAD3 genomes Cov.: 34

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 34

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2 Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jun 25, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jul 10, 2015	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	May 26, 2023	See Variant Classification Assertion Criteria. -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	May 07, 2021	- -

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 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 21, 2024

This sequence change replaces alanine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 2132 of the PLEC protein (p.Ala2132Met). This variant is present in population databases (no rsID available, gnomAD 0.04%). This variant has not been reported in the literature in individuals affected with PLEC-related conditions. ClinVar contains an entry for this variant (Variation ID: 281942). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -

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: rs886044784; hg19: chr8-144997783;