chr8-143932797-T-C

Position:

• chr8-143932797-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The ENST00000345136.8(PLEC):​c.1733A>G​(p.Asp578Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,144 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. D578D) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: PLEC ENST00000345136.8 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.52

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 These names were superseded by plectin.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
• BP4: Computational evidence support a benign effect (MetaRNN=0.3250792).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PLEC	NM_201384.3	c.1733A>G	p.Asp578Gly	missense_variant	14/32	ENST00000345136.8	NP_958786.1
PLEC	NM_201378.4	c.1691A>G	p.Asp564Gly	missense_variant	14/32	ENST00000356346.7	NP_958780.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PLEC	ENST00000345136.8	c.1733A>G	p.Asp578Gly	missense_variant	14/32	1	NM_201384.3	ENSP00000344848
PLEC	ENST00000356346.7	c.1691A>G	p.Asp564Gly	missense_variant	14/32	1	NM_201378.4	ENSP00000348702

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152144 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 65

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152144 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74334

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Labcorp Genetics (formerly Invitae), Labcorp

Jul 19, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C65"). ClinVar contains an entry for this variant (Variation ID: 281224). This variant has not been reported in the literature in individuals affected with PLEC-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.007%). This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 605 of the PLEC protein (p.Asp605Gly). -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Sep 08, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.29
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.020
CADD	Benign	21
DANN	Benign	0.80
DEOGEN2	Benign	0.23	.;.;.;.;T;.;.;.;.;.;T
Eigen	Benign	-0.23
Eigen_PC	Benign	-0.20
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.73	D
MetaRNN	Benign	0.33	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.24	D
MutationAssessor	Uncertain	2.5	.;.;.;.;M;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.70	T
PROVEAN	Uncertain	-2.6	D;D;D;D;D;D;D;D;.;D;D
REVEL	Benign	0.18
Sift	Uncertain	0.0020	D;D;D;D;D;D;D;D;.;D;T
Sift4G	Uncertain	0.0060	D;D;D;D;D;D;D;D;.;D;T
Polyphen		0.085	B;B;B;B;B;B;B;B;.;.;.
Vest4		0.36
MutPred		0.24		.;.;.;.;Gain of MoRF binding (P = 0.0456);.;.;.;.;.;.;
MVP		0.62
ClinPred		0.83	D
GERP RS		5.0
Varity_R		0.47
gMVP		0.48

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: rs886044773; hg19: chr8-145006965;