chr8-143931631-C-T

Variant names:

• chr8-143931631-C-T
• rs951623918
• NM_201384.3:c.2207G>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_201384.3(PLEC):​c.2207G>A​(p.Gly736Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign 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. G736R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: PLEC NM_201384.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.38
• Publications: 2 publications found

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 These names were superseded by plectin.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]

PLEC Gene-Disease associations (from GenCC):

• epidermolysis bullosa simplex

  Inheritance: AD Classification: STRONG Submitted by: G2P
• epidermolysis bullosa simplex 5A, Ogna type

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, PanelApp Australia, Genomics England PanelApp
• autosomal recessive limb-girdle muscular dystrophy type 2Q

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)
• congenital myasthenic syndrome

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
• epidermolysis bullosa simplex 5B, with muscular dystrophy

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Orphanet, Genomics England PanelApp
• epidermolysis bullosa simplex 5C, with pyloric atresia

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• epidermolysis bullosa simplex with nail dystrophy

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia
• autosomal recessive limb-girdle muscular dystrophy

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen
• aplasia cutis congenita

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• cholestasis

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.034878314).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PLEC	NM_201384.3	c.2207G>A	p.Gly736Glu	missense_variant	Exon 19 of 32	ENST00000345136.8	NP_958786.1
PLEC	NM_201378.4	c.2165G>A	p.Gly722Glu	missense_variant	Exon 19 of 32	ENST00000356346.7	NP_958780.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PLEC	ENST00000345136.8	c.2207G>A	p.Gly736Glu	missense_variant	Exon 19 of 32	1	NM_201384.3	ENSP00000344848.3
PLEC	ENST00000356346.7	c.2165G>A	p.Gly722Glu	missense_variant	Exon 19 of 32	1	NM_201378.4	ENSP00000348702.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00 AC: 0 AN: 221884 AF XY: 0.00

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1448012 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 718910

African (AFR) AF: 0.00 AC: 0 AN: 33304

American (AMR) AF: 0.00 AC: 0 AN: 43038

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25804

East Asian (EAS) AF: 0.00 AC: 0 AN: 39198

South Asian (SAS) AF: 0.00 AC: 0 AN: 83860

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51086

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5748

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1106100

Other (OTH) AF: 0.00 AC: 0 AN: 59874

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

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

Jul 04, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. 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 output the following: (SIFT: "Tolerated"; PolyPhen-2: "Unknown"; Align-GVGD: "Class C0"). The glutamic acid amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a PLEC-related disease. This sequence change replaces glycine with glutamic acid at codon 763 of the PLEC protein (p.Gly763Glu). The glycine residue is weakly conserved and there is a moderate physicochemical difference between glycine and glutamic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.071
BayesDel_addAF	Benign	-0.078	T
BayesDel_noAF	Benign	-0.35
CADD	Benign	16
DANN	Benign	0.87
DEOGEN2	Benign	0.050	.;.;.;.;T;.;.;.;.;.
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.029	N
LIST_S2	Benign	0.71	T;T;T;T;T;T;T;T;T;T
M_CAP	Uncertain	0.23	D
MetaRNN	Benign	0.035	T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.61	T
MutationAssessor	Benign	-2.1	.;.;.;.;N;.;.;.;.;.
PhyloP100		2.4
PrimateAI	Benign	0.41	T
PROVEAN	Benign	1.9	N;N;N;N;N;N;N;N;.;N
REVEL	Benign	0.15
Sift	Benign	1.0	T;T;T;T;T;T;T;T;.;T
Sift4G	Benign	1.0	T;T;T;T;T;T;T;T;.;T
Polyphen		0.0	B;B;B;B;B;B;B;B;.;.
Vest4		0.17
MutPred		0.37		.;.;.;.;Gain of disorder (P = 0.0576);.;.;.;.;.;
MVP		0.34
ClinPred		0.17	T
GERP RS		2.5
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.8
Varity_R		0.089
gMVP		0.22
Mutation Taster		=68/32	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs951623918; hg19: chr8-145005799;