rs776537364

chr1-209634547-G-GA

Variant summary

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

The NM_000228.3(LAMB3):c.463_464insT(p.Ser155PhefsTer27) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000384 in 1,614,024 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000040 ( 0 hom. )

Consequence

LAMB3
NM_000228.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: -0.674

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 1-209634547-G-GA is Pathogenic according to our data. Variant chr1-209634547-G-GA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188937.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMB3	NM_000228.3 linkuse as main transcript	c.463_464insT	p.Ser155PhefsTer27	frameshift_variant	6/23	ENST00000356082.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
LAMB3	ENST00000356082.9 linkuse as main transcript	c.463_464insT	p.Ser155PhefsTer27	frameshift_variant	6/23	1	NM_000228.3	P1
LAMB3	ENST00000367030.7 linkuse as main transcript	c.463_464insT	p.Ser155PhefsTer27	frameshift_variant	6/23	1		P1
LAMB3	ENST00000391911.5 linkuse as main transcript	c.463_464insT	p.Ser155PhefsTer27	frameshift_variant	5/22	1		P1
LAMB3	ENST00000415782.1 linkuse as main transcript	c.463_464insT	p.Ser155PhefsTer27	frameshift_variant	6/6	2

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152136

Hom.:

Cov.:

show subpopulations

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251300

Hom.:

AF XY:

0.0000294

AC XY:

AN XY:

135848

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:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000404

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.0000371

AC XY:

AN XY:

727244

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000522

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152136

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74326

show subpopulations

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:

0.0000441

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

ClinVar

Significance: Pathogenic/Likely 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

Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Nov 13, 2017	Variant summary: The LAMB3 c.463dupT (p.Ser155PhefsX27) variant results in a premature termination codon, predicted to cause a truncated or absent LAMB3 protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory (e.g. c.1365_1366delCA, p.Asn456fsX7; c.1903C>T, p.Arg635X). One in silico tool predicts a damaging outcome for this variant. This variant was found in 4/246120 control chromosomes at a frequency of 0.0000163, which does not exceed the estimated maximal expected allele frequency of a pathogenic LAMB3 variant (0.0009317). The variant has been reported in at least 3 affected individuals in the literature. In addition, one clinical diagnostic laboratory/reputable database classified this variant as likely pathogenic. Taken together, this variant is classified as likely pathogenic. -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Aug 25, 2014	- -

Junctional epidermolysis bullosa gravis of Herlitz;C0268374:Junctional epidermolysis bullosa, non-Herlitz type;C4011403:Amelogenesis imperfecta type 1A

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Mar 21, 2022

- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jul 12, 2022

This sequence change creates a premature translational stop signal (p.Ser155Phefs*27) 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 (rs776537364, gnomAD 0.004%). This premature translational stop signal has been observed in individual(s) with junctional epidermolysis bullosa (PMID: 8824879, 11023379; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 188937). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.12

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