rs80356683

Positions:

chr1-183215467-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_005562.3(LAMC2):c.283C>T(p.Arg95Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,836 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 (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

LAMC2
NM_005562.3 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4O:1

Conservation

PhyloP100: 0.628

Variant links:

Genes affected

LAMC2 (HGNC:6493): (laminin subunit gamma 2) Laminins, a family of extracellular matrix glycoproteins, are the major noncollagenous constituent of basement membranes. They have been implicated in a wide variety of biological processes including cell adhesion, differentiation, migration, signaling, neurite outgrowth and metastasis. Laminins, composed of 3 non identical chains: laminin alpha, beta and gamma (formerly A, B1, and B2, respectively), have a cruciform structure consisting of 3 short arms, each formed by a different chain, and a long arm composed of all 3 chains. Each laminin chain is a multidomain protein encoded by a distinct gene. Several isoforms of each chain have been described. Different alpha, beta and gamma chain isomers combine to give rise to different heterotrimeric laminin isoforms which are designated by Arabic numerals in the order of their discovery, i.e. alpha1beta1gamma1 heterotrimer is laminin 1. The biological functions of the different chains and trimer molecules are largely unknown, but some of the chains have been shown to differ with respect to their tissue distribution, presumably reflecting diverse functions in vivo. This gene encodes the gamma chain isoform laminin, gamma 2. The gamma 2 chain, formerly thought to be a truncated version of beta chain (B2t), is highly homologous to the gamma 1 chain; however, it lacks domain VI, and domains V, IV and III are shorter. It is expressed in several fetal tissues but differently from gamma 1, and is specifically localized to epithelial cells in skin, lung and kidney. The gamma 2 chain together with alpha 3 and beta 3 chains constitute laminin 5 (earlier known as kalinin), which is an integral part of the anchoring filaments that connect epithelial cells to the underlying basement membrane. The epithelium-specific expression of the gamma 2 chain implied its role as an epithelium attachment molecule, and mutations in this gene have been associated with junctional epidermolysis bullosa, a skin disease characterized by blisters due to disruption of the epidermal-dermal junction. Two transcript variants resulting from alternative splicing of the 3' terminal exon, and encoding different isoforms of gamma 2 chain, have been described. The two variants are differentially expressed in embryonic tissues, however, the biological significance of the two forms is not known. Transcript variants utilizing alternative polyA_signal have also been noted in literature. [provided by RefSeq, Aug 2011]

LAMC2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 1-183215467-C-T is Pathogenic according to our data. Variant chr1-183215467-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 14555.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-183215467-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMC2	NM_005562.3 linkuse as main transcript	c.283C>T	p.Arg95Ter	stop_gained	3/23	ENST00000264144.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMC2	ENST00000264144.5 linkuse as main transcript	c.283C>T	p.Arg95Ter	stop_gained	3/23	1	NM_005562.3	P1	Q13753-1
LAMC2	ENST00000493293.5 linkuse as main transcript	c.283C>T	p.Arg95Ter	stop_gained	3/22	1			Q13753-2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251448

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135894

show subpopulations

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461836

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727212

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.00000450

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Epidermolysis bullosa, junctional 3B, severe

Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Mar 29, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Jun 24, 2022	Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as pathogenic. The following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with Herlitz junctional epidermolysis bullosa (MIM#226700) and non-Herlitz junctional epidermolysis bullosa (MIM#226650). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0201 - Variant is predicted to cause nonsense-mediated decay (NMD) and loss of protein (premature termination codon is located at least 54 nucleotides upstream of the final exon-exon junction). (SP) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2) <0.01 for a recessive condition (1 heterozygote, 0 homozygotes). (SP) 0701 - Other NMD predicted variants comparable to the one identified in this case have very strong previous evidence for pathogenicity (ClinVar). (SP) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been reported as a recurrent variant in patients with junctional epidermolysis bullosa, including in the homozygous state in at least two patient with Herlitz junctional epidermolysis bullosa (ClinVar, PMID: 17916201). (SP) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Junctional epidermolysis bullosa gravis of Herlitz

Pathogenic:1Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Nov 11, 2019	NM_005562.2(LAMC2):c.283C>T(R95) is classified as pathogenic in the context of LAMC2-related junctional epidermolysis bullosa. Sources cited for classification include the following: PMID 17916201, 9085255, 15373767, 8012394 and 8983017. Classification of NM_005562.2(LAMC2):c.283C>T(R95) is based on the following criteria: The variant causes a premature termination codon that is expected to be targeted by nonsense-mediated mRNA decay and is reported in individuals with the relevant phenotype. Please note: this variant was assessed in the context of healthy population screening. -
not provided, no classification provided	literature only	GeneReviews	-	- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jun 02, 2023

ClinVar contains an entry for this variant (Variation ID: 14555). This premature translational stop signal has been observed in individual(s) with junctional epidermolysis bullosa (PMID: 8012394). This variant is present in population databases (rs80356683, gnomAD 0.003%). This sequence change creates a premature translational stop signal (p.Arg95*) in the LAMC2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in LAMC2 are known to be pathogenic (PMID: 11907499, 16473856). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.56

BayesDel_noAF

Pathogenic

0.29

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.44

Eigen_PC

Benign

0.15

FATHMM_MKL

Benign

0.096

MutationTaster

Benign

1.0

A;A

Vest4

0.83

GERP RS

4.0

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over