rs146794392

Positions:

Variant summary

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

The NM_000228.3(LAMB3):c.1978C>T(p.Arg660Ter) variant causes a stop gained, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,612,492 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R660R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

LAMB3
NM_000228.3 stop_gained, splice_region

Scores

Splicing: ADA: 0.0004724

Clinical Significance

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

Conservation

PhyloP100: -0.00500

Variant links:

Genes affected

LAMB3 (HGNC:6490): (laminin subunit beta 3) The product encoded by this gene is a laminin that belongs to a family of basement membrane proteins. This protein is a beta subunit laminin, which together with an alpha and a gamma subunit, forms laminin-5. Mutations in this gene cause epidermolysis bullosa junctional Herlitz type, and generalized atrophic benign epidermolysis bullosa, diseases that are characterized by blistering of the skin. Multiple alternatively spliced transcript variants that encode the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

LAMB3 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 1-209623999-G-A is Pathogenic according to our data. Variant chr1-209623999-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 189034.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-209623999-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMB3	NM_000228.3 linkuse as main transcript	c.1978C>T	p.Arg660Ter	stop_gained, splice_region_variant	15/23	ENST00000356082.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
LAMB3	ENST00000356082.9 linkuse as main transcript	c.1978C>T	p.Arg660Ter	stop_gained, splice_region_variant	15/23	1	NM_000228.3	P1
LAMB3	ENST00000367030.7 linkuse as main transcript	c.1978C>T	p.Arg660Ter	stop_gained, splice_region_variant	15/23	1		P1
LAMB3	ENST00000391911.5 linkuse as main transcript	c.1978C>T	p.Arg660Ter	stop_gained, splice_region_variant	14/22	1		P1

Frequencies

GnomAD3 genomes

AF:

0.0000591

AC:

AN:

152168

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000193

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

GnomAD3 exomes

AF:

0.0000200

AC:

AN:

249798

Hom.:

AF XY:

0.0000148

AC XY:

AN XY:

135244

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000654

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000205

AC:

AN:

1460208

Hom.:

Cov.:

AF XY:

0.0000234

AC XY:

AN XY:

726524

show subpopulations

Gnomad4 AFR exome

AF:

0.000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000720

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000591

AC:

AN:

152284

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.000193

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:

0.0000119

Hom.:

Bravo

AF:

0.0000567

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Junctional epidermolysis bullosa gravis of Herlitz

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Dec 10, 2018	Variant summary: LAMB3 c.1978C>T (p.Arg660X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 2.2e-05 in 275670 control chromosomes (gnomAD). c.1978C>T has been reported in the literature in multiple individuals affected with Junctional Epidermolysis Bullosa (Christiano_1997, Yuen_2011, Varki_2006). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. A ClinVar submission from a clinical diagnostic laboratory (evaluation after 2014) cites the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Counsyl	Jun 30, 2016	- -

not provided

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 12, 2024	This sequence change creates a premature translational stop signal (p.Arg660*) in the LAMB3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in LAMB3 are known to be pathogenic (PMID: 11023379, 16473856). This variant is present in population databases (rs146794392, gnomAD 0.02%). This premature translational stop signal has been observed in individuals with autosomal recessive junctional epidermolysis bullosa (PMID: 9160387, 21801158). ClinVar contains an entry for this variant (Variation ID: 189034). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Aug 12, 2022	Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 16473856, 12813757, 8824879, 21801158, 9160387) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.27

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Benign

-0.037

Eigen_PC

Benign

-0.38

FATHMM_MKL

Benign

0.20

MutationTaster

Benign

1.0

A;A;A

Vest4

0.57

GERP RS

-0.69

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.00047

dbscSNV1_RF

Benign

0.30

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